The Isles of Scilly, an archipelago of approximately 150 islands, are located some 45 km (28 mi) southwest of the westernmost point of England (Land's End). The islands are an erosional remnant of an ancient granite intrusion, and are notable because they have been inhabited for over 4,000 years. Only five of the islands are currently inhabited. Historical and geological evidence indicates that many of the islands were larger and/or connected in the recent past. Even today, it is possible to walk between certain islands during low tides. Image courtesy of NASA.