Learn about the Ancient Ohio Trail and its cluster of mysterious geometric earthworks left behind by pre-Columbian mound-builder cultures. Then get an inside look at the World Monuments Fund's biennial selection of endangered archaeological and cultural sites, whose preservation is vital to our heritage. And what goes up, must come down: Pilot Mark Vanhoenacker shares the physics, and the magic, of landing an airplane.

For more information on Travel with Rick Steves - including episode descriptions, program archives and related details - visit www.ricksteves.com.