Age of Empires IV: Anniversary Edition

Set up a skirmish match and set both you and the enemy on the same team, this will allow you to free build your base up without the risk of attack. Whilst you're at it, set your starting age to Age IV with high starting resources.

Once you have gotten into the game and progressed to build the House of wisdom with the Abbasid Dynasty faction you will notice that the building emits a gold footprint around this building. To extend this effect to other buildings have to be within that initial distance to make their own "footprint" glow gold too.

Once you've 'connected' 60 buildings within this glowing area you will have reached the third tier of the Golden Age and the achievement should pop shortly afterward in the match.