Long Island in Poole Harbour has gone on sale for the first time in 250 years, and is expected to sell for more than £1m.
The island is one of five in Poole Harbour, Dorset, the second largest natural harbour in the world.
To reach Long Island, visitors have to travel by boat, or can take a one-hour journey from London by helicopter.
Potential buyers arriving in luxury boats have been ferried ashore on flat-bottomed Poole canoes.
The island boasts beaches, cliffs, heath land, salt marshes and both evergreen and deciduous woodland.
Long Island attracts deer, foxes and small mammals from the mainland as well as sea, wading and woodland birds.
As a Site of Site of Special Scientific Interest, Long Island is protected by English Nature.
The isolated location offers wide appeal to buyers, but uninvited visitors are known to use it at times.
There is a rich and diverse plant life because of the variety of habitats on the island.
From Long Island you can see the Purbeck hills, the ruins of Corfe Castle, and the commercial port at Poole.
The owners hope the prestige of owning an island will attract potential buyers to Poole Harbour.