Tomb Raider I-III Remastered Starring Lara Croft

Tomb Raider 1 - Atlantis (Level 14)

You will enter a room with a a golden pyramid on the left (second one of the level) and water down below on the right. You need to jump in the water, use a switch on the right that activates a 40 second timer for the exit door. Swim back and get up the ledge and tall pillar. Use a running jump to land on the sloped left pillar ahead. Keep holding Jump and you will spring back to the shallow slope you can walk on (this is the one surface square you can touch). Quickly pivot towards the exit door, tap down to jump back, then do a running jump to dodge the boulder and land beside the open door. Run through for the achievement.

(There is a secret, a second boulder and items in the previous room so return if you want those - you can find a switch to open another door backwards if the one you passed closes behind you)

Video:

In the second room of Atlantis, room where there is a pyramid and water and where the second secret is, you need to go in the water action the lever, back to entry. You have to go at the end of the room with touching only on block of pyramid.
To do that you need to jump forward on black block where you will slide, you jump on the pyramid block. The rock will fall, jump fast on the end of room platform.
With this path you only touch one time the pyramid.
After success fall you can back up take secret 2