Suggestions for 1 hour challenge

I am going to enter the one hour challenge, but i have no ideas.

So to make the map better I want to see what other people want.

If you have any map ideas please tell me.

Thanks.

 

Something like an open terrain map set in Earth's Ediacaran period. No life, and as such, the land is very barren. The only life would be in the ocean at the time.

 

realistic jumps over rivers