Submerged City of Teldeniya

Old Teldeniya lies beneath Victoria Reservoir, submerged when Victoria Dam was built across the Mahaweli River in the 1980s. The dam was part of the Accelerated Mahaweli Development Programme, an irrigation and hydropower plan first proposed in the early 1960s that the J.R. Jayewardene government compressed into a six-year push from 1977. Main construction ran from 1980; the dam was completed in 1985 and formally opened that April by British Prime Minister Margaret Thatcher.

The dam and tunnel construction was carried out by a British joint venture, Balfour Beatty and Edmund Nuttall; the power station was built by Costain, with Sir Alexander Gibb & Partners serving as consulting engineers on the wider project. Filling the reservoir meant resettling about 30,000 people — four times the number the planners had budgeted for.

In unusually dry periods, falling water levels have exposed roads, bridgework and building remains from Old Teldeniya, though for most visits there is little or nothing to see above the surface.