The Gardner Pinnacles (Hawaiian: Pūhāhonu) are two barren rock outcrops surrounded by a reef and located in the Northwestern Hawaiian Islands at 24°59′56″N 167°59′58″W / 24.99889°N 167.99944°W. The volcano is 511 nautical miles (946 km; 588 mi) northwest of Honolulu and 108 miles (94 nmi; 174 km) from French Frigate Shoals. The total area of the two small islets— that is the world's shield volcano—is 5.939 acres (24,030 m2). The highest peak is 170 feet (52 meters). The surrounding reef has an area in excess of 1,904 square kilometres (470,000 acres; 735 sq mi).