What are some inexpensive materials that would be good for building a very small

Question:

What are some inexpensive materials that would be good for building a very small model of an ancient greek...?

...of an ancient Greek amphitheater in a school assignment?

Best Answer - Chosen by Asker:

http://www.roadsideamerica.com/attract/v...

Some sort of harder styrofoam? I admire the concept...

Or maybe rice krispies and marshmallows. (Just kidding but you could eat it after class.)