The Sunken Roads

Stone roads and carved gates beneath Lake Surmave, built by the unknown Builders of the Age of Ruins before the Reckoning. Divers keep finding more of them, and the Drowned Court's Gatekeepers are the only people who will go down to them, which is why Caelvenne's cardinals leave the faith alone: the Nine Houses want to know what is there. They belong to the same lost age as the black-stone foundations under half the great cities of Aethorra, and what lies under the lake is one of the open questions of 1146.

See also: The Drowned Gate, The Drowned City, Lake Surmave