Minecraft: Xbox 360 Edition

This is a simple way I've found on youtube (see video at the end of the solution).
It worked for me, and I've done it using only one bucket to carry lava and water.

EDIT: After the Title Update 12 in the tutorial level you can find a bucket in the castle, and a lava pool near the sea after the castle.

In the Brewing Room there is a chest with a bucket:


On the other side of the castle you can see the sea, a lake, and a lava pool:




The video guide is made by gamersgonnaplay, not mine.

Method 1:

Items needed:
14 Obsidian
Flint & Steel

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Gaining Obsidian

In order to gain Obsidian you need to find a place underground where lava mixes with water, and then mine said spot. Said block looks like this

Although in order to mine Obsidian you need to mine it with a Diamond pickaxe. To gain a diamond pickaxe you need to mine 3 diamond rocks with an iron pickaxe or higher and then craft them using the crafting machine. Diamond rocks looks like this

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Gaining Flint & Steel

Flint & Steel is created by using flint and an iron ingot (Derived from Iron ore) in a crafting machine.

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Building the Portal

With your Obsidian blocks build the basic portal shape, 4 blocks wide and 5 blocks tall. Then use your flint & Steel on top of one of the Obsidian blocks on the bottom of the portal. The empty space inside the portal will turn purple and voila, achievement unlocked.

Method 2:
Friend who has a nether portal already constructed

Join your friends world and meet him at the portal, if the portal is alight (Purple glow in the empty space) mine away an obsidian block and when the block is replaced the portal will be unlit.

Grab your flint & steel and simply re-light the portal. This will net you the achievement.

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Update #1 - Credit to Eskimoletdinov

Instead of finding a unique mine in which both water and lava co-exist it is possible to bring along buckets of water, and use them on the lava to make Obsidian. Be careful though as you may slip into the lava and die!

To create buckets you need to have iron ore, then smelt it into an iron ingot, and then create a bucket with it in the crafting table.

This is a guide on how to get this achievement WITHOUT DIAMOND. It's very hard to explain in words so I've included a video of the steps down below. Any questions feel free to leave a comment and I will answer.

To get this achievement you need to make a 4 x 5 block vertically oriented portal to the other dimension, The Nether, by building it from obsidian and then igniting the bottom interior surface with a flint & steel.

Obsidian can be found deep underground where water flows onto lave pools, but I find the the easiest way to make obsidian is to find an existing lava pool (you can sometimes find them on, or close to, the surface), then take a bucket of water and pour it so that it flows over the lava surface. You can then mine the obsidian with a diamond pickaxe. Depending on where you poured it, the water will also flow into the gaps you make, making more obsidian if it comes into other lava deposits beneath. Note that the water has to be poured on pooled, not flowing lava.

You can omit the four corners of the portal, so it only requires 10 blocks of obsidian rather than 14.

I created this guide for people that have troubles at finding lava like I did. I made a video to show where to find lava near the first village and how to create the portal without being required the Diamond pickaxe.

After completing the tutorial we'll have access to the first village. When we are at that place we'll have to get the items that i listed below.

a) We need to find some Flint, Coal, and Iron ore to create Iron Igot .

Iron ore

Coal

Flint

Iron Igot



b) Next we create a Flint and steel.( 1 Flint and Steel = 1 Iron Igot + 1 Flit )

Flint and Steel



c) Finally we create some buckets (as more we have, more faster will be). ( 1 Bucket = 3 Iron Igot )

Bucket


After this just follow my video....

If you are playing on the tutorial level, then there is a pool of surface lava near the first village. You can get seven buckets total from it. There is also a massive cave system just across the water and ice from the first village as well in the tutorial world, where you can not only find several good pools of lava right at the bottom, but also about six diamonds. You can also find tons upon tons of iron, as well as a fair few pieces of gold ore, as well as redstone for the 'On a Rail' achievement. Bearing in mind you only need 10 blocks of obsidian to make a portal, you will only need three buckets worth of lava from the cave if you used the surface pool right near the first village. Again, this is all on the tutorial level. I hope this helped.

10/16/12 EDIT: The New 1.8.2 patch regenerated the world, so my ore locations no longer work. The pre-made portal has also moved. If you generate the tutorial world with the update required to play online, the older guide will not work correctly.

The portal is found taking the left hand branch of the mountain cave that can be seen from spawn. Use the automatic bridge builder to access the cave. The portal itself is hidden behind a piston door. The lever to open it is hidden in a hole in the ceiling.

There's a load of iron in the area around X -81, Y 57, Z 10, pretty close to spawn and some of it's easily visible without even digging. A furnace can be found in the village just outside spawn, flint can be acquired from the gravel path leading out of spawn.

You need a bucket and flint & steel, so make them, fill the bucket with water and go to the mountain. Once you're at the portal, use blocks to direct the water into the portal. That will deactivate it and you can relight it (using the flint and steel) after removing the water.

Note that using Creative mode will void any and all achievements.


If you have access to the 1.7 update tutorial, here's the original guide:

The Tutorial world after the update from July 13th has a prebuilt Nether portal hidden in the giant Minecraft sign. (Use a pillar of dirt to reach the small sides, there's a lever on each that opens a door.) Deactivating it with a bucket of water and then reactivating with a flint and steel gets you the achievement with no lava molding required.

Since it still requires the bucket and flint and steel, the only thing this saves you doing is making the mold (and with one bucket that can take some time), as there is a very large pool of lava near the castle by the village. Still, it's worth noting that there's a molding-free method. (Also, my guide below provides confirmed iron and coal locations within a short distance of spawn, so even if you mold, it'll probably help.)


In-depth guide:

Getting flint is simple, just break the gravel in the village until you get one. Iron is trickier, but there's a guaranteed vein of eight at the coordinates X: -46 Y: 64 Z:-175. This is enough for a bucket and a flint and steel, as well as four leftover ingots. (Use them at your leisure.) There's a vein of four coal right nearby at -45, 70, -187, one coal is enough to smelt all the iron. (No tool is required to get flint, it's just a random drop. Coal is any pickaxe, Iron is stone pickaxe or better.)

Since you're going back to the village anyway to reach the sign, you can use the furnace that's in the house with the iron door instead of having to make a furnace. (Although you can make one if you need the achievement, up to you. 8 cobblestone is no big deal to get.) Once you have your iron and flint, make a flint and steel and a bucket.

Reaching the sign will require about 20 blocks, just make a dirt pillar below you. You want to be on the shortest sides, the levers are easily visible from outside. (If this is your first time in the tutorial, it'll even offer a tutorial about the Nether.) Place a couple of blocks so your water flows through the portal, and it'll deactivate. Then just look at the lower inner surface and hit left trigger with your flint and steel equipped. Achievement should pop, 40 GS, and if you don't already have them you can get six others along the way. Shouldn't take more than ten minutes.

EDIT: Some more Iron and Coal locations in the tutorial world:

Seven Iron Ore: X: -134, Y: 64, Z: 73 (In a cave under the iron door house in the village, there's an eighth Ore block nearby as well, I assume the cave overwrote the rest of the second vein.)

Ten Coal and One Iron: X: -113, Y: 61, Z: 49 (Also in the cave under the iron door house. The Coal vein may have overwritten most of the Iron vein.)

More Coal: X: -82, Y: 70, Z: 41 (Should be outside, but I figured I'd mention it because it could com in handy.)

Also, because I didn't mention it before, the map you start with displays your XYZ coordinates. Use it to find these spots.

It is also possible if you find a server or have a friend who already got this achievement, just destory one of the blocks on the bottom or on top, then just place it back.
Lit the portal with Flint & Steel and achievement unlocked!

I found a very simple way of doing this achievement. This was unlocked yesterday so the method should work until any update comes through. The best thing is, you do not need any Lava, which cuts out so much time.

1.You want to start on the Tutorial level. You will spawn beside an unfinished wooden hut with a few ponds nearby and various animals running around. I believe this is the standard spawn point for the tutorial. If you do not spawn here, either go and explore for the castle (under the Minecraft sign in the sky) or start again.

2. Finish the basic tutorials until the game advises you that you can move to the next area. At this point, follow the Craft menu to create a Flint and Steel. This is the only tool you will need to construct. There is plenty of gravel in this area so mine to your hearts content. There will also be iron underground if you dig down. There is a bed in the castle nearby if you need daylight. This process took me about 10-15 minutes (could be less dependant on luck).

3. When you do this, you head through a wooden hut with a chest in it. This contains a Music Disc. When you leave this building, you have the interior of a castle dead ahead, a doorway left and right which lead to the world outside. You do not need to leave this castle. Head straight ahead.

4. Inside the castle (you know you are in the right place if you see a duel set of stairs heading up. Keep this in mind because you will return here). Turn left and you should see a library looking room. There is a chest in here, which contains Diamond tools. You need to take the Diamond Pickaxe.

5. Head back to the stairs, head up, turn around and you should see a wall dead ahead with a small doorlike shape in it. Make a hole in this wall. Voila, you should see a window dead ahead and on your right is a PORTAL.You know you are in the right place as the windows look out across the path you just walked up (from the first area).

6. All you need to do is break one of the obsidian blocks that construct the portal to turn it off. Use the Diamond pickaxe for this. Then place the block back onto it. With your Flint and Steel, hit the bottom Obsidian block and voila, achievement unlocked!

What I did to earn this achievement, was:

1. Go to the tutorial
2. Find the room with the diamond pick-axe and get it (its in a chest in the library)
3. Go to the nether room
4. Break a nether block piece with the diamond pick-axe and collect it
5. Put it back and light it with flint and steel (which you need to craft) and you will get the achievement.

This one is fairly easy to achieve, providing you know what to do. If you have already collected some diamonds previously, craft a pickaxe and four buckets and use the buckets to collect some water from a nearby source. When you have these items, proceed down into a dungeon and begin searching for a lava pool. When you find one, use the buckets of water around the pool. You will notice that the lava turns to obsidian as soon as it is touched by water. You will need 14 blocks of obsidian to complete the structure of the portal, so make sure to distribute the water evenly (or take more buckets with you). Once you have done this, you can harvest the obsidian by using your diamond pickaxe on it (note: only the diamond variation of this tool will work). You will also need iron and flint (which can be harvested from gravel) to create the Flint & Steel tool which will allow you to light your portal. When completed, you can start building your Nether portal.

Alternatively, if you do not yet have any diamonds, you can fill your inventory with empty buckets and seek out a lava pool. Collect as much lava as you can carry (leaving three empty spaces in your inventory) and then collect one bucket of water. You will then need some dirt blocks (I’ll explain later), I suggest around thirty. You will also need the Flint & Steel tool. Now, choose your destination on where you want to build the portal. Place the bucket of lava on one block and then place the bucket of water on a block anywhere providing it is beside it in quick procession. You will notice that the water turns the lava to obsidian. Do this all the way around. The structure of your portal should always look like this (X representing the Obsidian block and O representing the area within):

X X X X Dimension: 4 x 5 blocks
X OO X
X OO X
X OO X
X X X X

The dirt I told you to hold previously will come in handy for doing the blocks of the portal which are higher up. Simply level the dirt with the structure of the portal to make it higher. You can go back and delete the dirt at a later point. Once the structure is complete, you can then light the obsidian using the Flint & Steel tool. (Click here to see an example of building a Nether portal with lava and water.) You will now have your achievement!

I found a way to do this without having to find diamond.
1.You will need buckets for this, they need three iron ingots each to make.
2.Collect lava with them
3. Find a place to build your portal
4.You need to create a framework for your base with dirt, 3x3 with the two middle blocks empty.
5.fill on of the middle blocks with lava
6. collect water and empty it nest to your lava
7.collect the water and repeat with the other side
8.put on block on top of each obsidian, leave the one nest to it open and build a frame around it. do this for both sides
9.put lava in the hole and place the water next to it
10.collect and repeat on the other side
11.build the frame one level higher and repeat steps 9 and 10
12.repeat step 11
13.put blocks next to the obsidian on the inside of the portal
14.build a frame so that there are two open blocks
15. fill one with lava
16.place water next to lava
17.repeat on the other side
18. destroy any blocks that aren't obsidian
19. light with flint and steel.

If you down vote this solution, please let me know why so I can make it better, thank you.

i was going to go to the ender portal and go to the dragon and kill it and take the blocks that the towers are made out of

here is a link to a youtube video to show you how to get Into The Nether Achievement in Minecraft Xbox 360 Edition If you liked the video please remember to leave a rating, helps me out a lot :D