CINTRA, a town of Portugal, province of Estremadura, 14 miles N.W. of Lisbon, with about 4000 inhabitants. It stands at the foot of a stupendous rocky mountain, and is remarkable for the picturesque beauty of its situation and the salubrity of its climate, which render it a favourite resort of the wealthier inhabitants of Lisbon. On one of the adjacent summits stands the Penha convent; and on another are the ruins of a Moorish castle. It has also an ancient royal palace. The convention, by which the French were allowed to leave Portugal without molestation, was signed at Cintra, August 22, 1808.