At the entrance of the harbour is the castle of San Felipe, on a neck of land between Port Mahon and St. Stephen’s Cove. The main fort consisted of four bastions connected by curtains, with a deep ditch hewn out of the solid rocks. Within the area there were the Governor’s house, barracks, guard-room, and chapel. In the centre there was a pump to supply the troops with rain water from a large cistern. The whole rock is undermined with subterranean passages and chambers. A considerable suburb, including barracks and officers’ quarters, rose up outside the castle. The plain beyond is stony and barren, but at the head of St. Stephen’s Cove there is a _barranco_ or ravine, bounded by rocks on either side, where there are fruit trees and garden vegetables of all kinds. These _barrancos_ are the fertile and fruit-yielding parts of the island. Originally long creeks penetrating into the land from the sea, they have been gradually filled with rich soil by floods from the hills on the north side, until they were raised above the sea level. There is no tide to carry off the deposits brought down from the hills. At the upper end of the harbour there is another extensive _barranco_, known as the gardens of San Juan, which was the principal source of supply of vegetables for Mahon. A few miles farther north is the _albufera_, or salt lake, separated from the sea by a sand-spit, and abounding in fish; and still farther to the north are the harbour and beautiful valley of Adaia. Wild pigeons and rabbits frequent the rocky cliffs and islands on the coast. The interior of the island is barren and stony, except for the _barrancos_. Alaior was a tolerably well-built town on an eminence; but Mercadal and Fererias are only wretched villages. The north coast is deeply indented, and Port Fornelle is a large harbour.