Lisbon Cathedral

The oldest church in Lisbon, begun in 1147 shortly after the city was taken from Moorish rule, this fortress-like cathedral has been rebuilt many times after earthquakes reshaped its outline. Its twin crenellated towers and rose window front a mostly Romanesque nave that gives way to a Gothic ambulatory and a cloister where archaeologists uncovered Roman and medieval remains. Visitors can reach the treasury and walk the excavated ruins, tracing centuries of the city's layered past beneath one roof.