Lisbon, Portugal

Lisbon sits where the Tagus widens into an inland sea before reaching the Atlantic, and the city climbs the hills on its northern bank. Its Islamic period ran from the eighth century to 1147, and while no mosque survives, the shape of that city does: the citadel on the highest hill, now inside the walls of São Jorge Castle, where excavation has exposed the foundations of the Islamic-period quarter; Alfama on the slope below, whose lanes and stairways are too narrow and too irregular to be anything but pre-conquest; and stretches of the wall known as the Cerca Moura still standing between houses. The Mouraria, on the other side of the castle hill, is where the Muslim population was resettled after 1147 and carries their name to this day. The great earthquake of 1755 destroyed the lower city and it was rebuilt as the Baixa, a rectilinear grid of uniform façades running down to the river — one of the first planned reconstructions in Europe. Westward along the water, Belém holds the Jerónimos monastery and the tower built to guard the harbour, both from the sixteenth century. Inland, half an hour by road, Sintra sits in a wooded range with the Castelo dos Mouros on the ridge above it: a tenth-century Muslim fortification whose curtain wall runs along the crest, with the remains of an Islamic quarter uncovered inside the walls.