If you have a way to keep people from touching it too much and destroying it, you can do alot of cool stuff with the 1 inch thick phone insulation boards from Home Depot (or wherever). You can create pretty decent stone, wood, and cement facades with it. Here's an example:
These lanterns on Amazon are battery powered, last a long time, have auto on/off, and provide a great ambiance:
With LEDs, you can run quite a bit off of a single extension cord. In the woods, you can get alot of bang for the buck with a projector and invisible screen. Plenty of ideas/products here: