Columbus was just one in a long line of trans-Atlantic travelers. On this week's Travel with Rick Steves, travel writer Tony Horwitz retraces the North American routes of 16th century explorers, and how they changed America before the big waves of European settlers arrived. And sailing expert Anthony Sandberg reveals what we'll find in today's hot spot for discovery - Antarctica.For more information on Travel with Rick Steves - including episode descriptions, program archives and related details - visit www.ricksteves.com.