Bear's Castle, Yan Yean Reservoir Reservation, Cades Lane, Yan Yean, is a probably unique structure built circa 1848 on a property farmed by Thomas Bear. The two storey structure is square in plan and is constructed apparently of cob with originally a shingled, pyramid shaped roof, now clad in corrugated iron . There are turrets at each corner, one with a stair and another in brick and stone with the chimney. Lancet windows are framed with branches.
Bear's Castle, Yan Yean Reservoir Reservation, Cades Lane, Yan Yean, is a particularly rare and unique building, both for its design and its constuction techniques. the building also has historical associations with the early pastoralists of the area. In the Picturesque Gothic Style, Bear's castle is an important example of the fashion for Picturesque structures which characterises English design in the early nineteenth century. The structure is equally important for the vernacular construction techniques used.
Bear's Castle, Yan Yean Reservoir Reservation, Cades Lane, Yan Yean, has been refaced and reroofed, but is believed to be very largely intact.
Of national significance.