What to do in Mongolia?

On my way back from China, I have the good fortune to have a bit of time to spend visiting a place I’ve always dreamed of- Mongolia. I’ll be able to spend about five nights there.

The big problem is, I know nothing about Mongolia except there are horses and yurts. I’m most interested in remote exotic places with interesting traditional cultures- although I know it may be tough to get too far out in so little time. A bit of adventure is a big plus. History is also good.

Any ideas?