For more than a century, the lighthouse at Granton was a busy depot for the Northern Lighthouse Board. The experimental tower with its lantern copula was added in 1874, though it never served as a working lighthouse. Instead, the sturdy red-brick warehouse was used to teach lighthouse keepers their trade and to experiment with new technologies of the time. But the story of the disused testing station is being rewritten – and will see it brought back to life as a beacon of a different kind.