So, as I see I'm the first who started to work on a map for a challenge.
There's a game called Dear Esther, I saw many screenshots and videos about it, and the first map starts at a lighthouse. It was on an abandoned island, and I decided to make something like that.
My concept is to make a small cliff with a lighthouse and some smaller houses (power supply or generator etc.)
Some layouts I've found for the lighthouse:




I'll post some concept drawings tomorrow or later