Guernsey Geography

Alderney, Guernsey, Herm, Sark, and some other smaller islands have a total area of 30 square miles (78 km2) and a coastline of about 30 miles (48 km). By itself, the island of Guernsey has a total area of 25 square miles (65 km2). Guernsey is situated 30 miles (48 km) west of France's Normandy coast and 75 miles (121 km) south of Weymouth, England and lies in the Gulf of St Malo. Lihou, a tidal island, is attached to Guernsey by a causeway at low tide. The terrain is mostly level with low hills in southwest.

Elevation varies across the bailiwick from sea level to 375 ft at Le Moulin on Sark. The highest point in mainland Guernsey is Hautnez (363 ft), in Alderney at Le Rond But (306 ft), in Jethou (248 ft) and Herm (322 ft). Natural resources include cropland.
Guernsey contains two main geographical regions, the Haut Pas, a high southern plateau, and the Bas Pas, a low lying and sandy northern region. In general terms, the Haut Pas is the more rural of the two, and the Bas Pas is more residential and industrialised.

There is a large, deepwater harbour at St Peter Port. The Casquets, a group of islets, are notable for the lighthouse facility constructed there.