No trip to Sevilla in Spain would be complete without a trip to the Catedral de Sevilla. Formerly a mosque, now it is a massive cathedral. If you visit, be sure not to miss La Giralda, the cathedral's belltower that used to be a minaret. The most spectacular views of the city are from the top of that tower. Also not to miss are Christopher Columbus's tomb, the Court of Oranges, and a prayer or two.