Round Island Lighthouse

Round Island Lighthouse is located to the northeast of Tresco Island and marks the most northerly point of the Isles of Scilly. The island is around six miles northeast of Bishop Rock and two and a half miles north of the island of St Mary’s.

Round Island is sizeable and housed the lighthouse tower, keepers’ cottages, a small garden and a helipad. The island has only ever been inhabited by lighthouse keepers.

Originally the approaches to the Isles of Scilly were marked from the south by St Agnes Lighthouse and to the west by Bishop Rock Lighthouse. 

The granite island rises 130 feet above sea level, and its sides are vertiginous, so building the lighthouse was challenging.  The sheer rock face made unloading materials for its construction extremely difficult.

There is a narrow channel between the landing steps and an outlying rock, from where lighthouse supplies used to be winched up via a Blondin cableway in the days before helicopter reliefs.

The 63-foot-high lighthouse tower is painted white, and its lantern is distinctively large. The lighthouse was designed and overseen by Sir William Tregarthen Douglass and was established in 1887.  It displayed a red flashing light every 30 seconds to make its location distinctive. Because the range of red light is smaller than white light, a huge hyperradial optic was installed to intensify the light.  This optic, the largest of the range, was manufactured by Chance Brothers of Smethwick. 

In 1967, the optic was replaced, and in 1987, a further optic was installed when the lighthouse was automated.  At the same time, the light character was changed to white flashing.

A corridor linked the keepers’ cottages to the tower, and a fog signal room was located nearby.

Round Island is not accessible, but boat trips head out frequently from St Mary’s, passing the island.  It is therefore possible to get good views from seaward.  It is also visible from the island of Tresco and St Martins.