This week on the Travel with Rick Steves radio show and podcast: A Dutch guide invites us to imagine a day on the water exploring Amsterdam's iconic canals. Then a historian shares what little we know of the elusive Sentinelese — likely the most isolated, least contacted people on earth — and what he learned by traveling to nearby islands in the Bay of Bengal. And a tour guide from Portugal tells us why the venerable university of town of Coimbra is such a delight to explore. Find your local sta