Included is a copy of the Infinite Universes. You can find the Contingent Seas very easily by attempting to reclaim Thizadil, the fortress founded by an expedition that didn't last a season. There are also a number of very, very curious geologic formations throughout the map, achieved by dropping EROSION_CYCLE_COUNT to 0 in the advanced worldgen parameters.

Also included is a DFMap file of the Seas itself (themselves?), viewable with Overseer.