Travel Trivia Tuesday 4

Amy, Laura and Claire, you really do know your Elvis history! As you correctly said in answer to last week's travel trivia question, the king of rock n' roll was born in Mississippi (Tupelo, Mississippi to be precise).Our destination of the month for March is Portugal, so here's the first of five brain teasers based on this holiday hotspot.Thanks to its wonderful setting (17 km from the Atlantic, on the north bank of the River Tagus) Portugal's cosmopolitan capital Lisbon is rightly considered to be one of the world's most beautiful cities.Visitors looking to experience the nation's culture are spoilt for choice in what was once a place of great importance, and home to some of history's most famous explorers. Great discoveries made in the late 15th century, and the conquest of the East Indies rapidly turned Lisbon into one of the wealthiest cities in Europe.This monument with 'world heritage' status is one of the many gems in Lisbon's treasure chest of beautiful architecture. Built in 1515 as a fortress to guard the harbour entrance, this was the starting point for many voyages of discovery. But what is it called?