The Bridge over the River Mullica...

is made of recycled plastic. Really interesting article from the Washington Post on this unique use of recycled material, and how it's proven itself a realistic alternative to wood for smaill bridge projects. The creators of the material aren't confident about the material being used on larger-scale projects (i.e. interstate bridges), but if every small wooden bridge in the country were replaced this way, we'd save a lot of forest land...