SAN SEBASTIAN, a city of Spain, in the province of Guipuscoa, at the mouth of the river Urumea, which runs from Navarre. Its harbour is excellent, and, as well as the city, is defended by the strong fortress La Mota, which overlooks both; and it has other powerful fortifications towards the land as well as the sea. It has considerable trade by means of ships of great burden. The mole is a magnificent and well-executed work, as is the lighthouse, which is visible at sea at nine leagues distance. San Sebastian has always been considered, for its extent, the most commercial city of Spain, and its trade is as ancient as its foundation. The city contains about seven hundred houses, mostly containing two or more families, and the population is 13,100 souls; but the country around it is thickly studded with country residences, and is well peopled. The land in its neighbourhood is not fertile, but the hills which surround it abound with iron, and are a great source of wealth to the inhabitants. It is in latitude 43. 19. 39. north, and longitude 1. 30. 35. west from London.