Hoy, island, 13 mi (21 km) long and 6 mi (9.7 km) wide, off N Scotland, second largest of the Orkney Islands. It is located at the southwestern side of the Scapa Flow anchorage. Ward Hill (1,565 ft/477 m) is one of many hills on the island; magnificent cliffs line the shore. There are some farms in the northeastern section, but the midland is a barren moor. Lyness, on the east coast, was headquarters of the Scapa Flow naval base. The Old Man of Hoy, a sandstone pinnacle 450 ft (137 m) high, is a famous sailors' landmark. The Dwarfie Stone, a huge sandstone block with hollowed rooms inside, is a Viking relic.