The oldest part of Lisbon, the Alfama quarter sprawls down the hillside from below the Castelo de Sao Jorge, retaining much of the traditional colour and atmosphere from the days when it was the ancient seat of the Saracens. Along the narrow cobblestone alleyways are taverns and street markets, interspersed with close-packed houses still occupied by stevedores, fishmongers and sailors. At the edge of the Alfama, Lisbon's renowned flea market, the Feira da Ladra, is held in the Campo de Santa Clara every Tuesday and Saturday. The Alfama is also full of historic buildings and churches, which are well worth exploring. Some of the buildings display fading coats of arms, which bear testimony to the fact that the Alfama was once home to aristocrats. At night the Alfama takes on a more mysterious aspect with street lanterns throwing shadows on the medieval walls, and it is advisable to avoid the area after dark in favour of the Bairro Alto café and nightclub district.