Belle Isle is the largest island on Windermere, about half a mile long, and sits in the main channel of the lake roughly opposite Bowness. It has been continuously inhabited since the seventeenth century and is privately owned, so you cannot land there — but it is visible from the shore and from any boat on the lake, and the unusual circular house at its centre is unmistakable once you know to look for it.
The house was built in 1774 for a Mr English, and its round plan was intended to give every room a view of the lake. Whether it succeeded aesthetically has been debated ever since. The island changed hands several times before being acquired by the Curwen family in 1781, who planted it with the trees that now make it look naturalistic. Windermere Lake Cruises boats pass close enough on some routes to give a good view from the water.