St James's Church, Dalehead , nr Clitheroe (also Gisburn Forest/Stocks Reservoir)
When the reservoir was built in 1932 the old St James's Chruch wasn't below the waterline, but concerns about contaminating the water supply meant they chose to relocate the building + graveyard about 1mile to its current location.
The old church foundations were lost but have been uncovered since and can be viewed with some info about the church and the reasons for its move.