Revealed: the world's top private islands for sale

Name: Alisa Craig Size: approx. 245 acres Price: Up to £2.75m ($4.5m) Location: Scotland. Lying 10 miles of the shore of the Firth of Clyde, the islands includes four cottages, a ruined castle and a lighthouse built in 1883. Formed from a volcanic plug, the island extends to about 2 miles in circumference and rises to an elevation of over 1100 feet above the sea. It is also home to a 'blue hone' granite quarry, known the world over as the source of granite for curling stones. *All images courtesy of Vladi Private Islands