The Seven Stones reef is a rocky reef nearly 15 miles (24 km) west-northwest (WNW) of Land's End, Cornwall and 7 miles (11 km) east-northeast (ENE) of the Isles of Scilly. The reef consists of two groups of rocks and is nearly 2 miles (3.2 km) long and 1 mile (1.6 km) in breadth. They rise out of deep water and are a navigational hazard for shipping with 71 named wrecks and an estimated 200 shipwrecks overall. The most infamous is the Torrey Canyon in 1967, which was at that time the world's costliest shipping disaster, and to date, still the worst oil spill on the coast of the United Kingdom.