Source: Into the Darklands, pg(s). 49
Niovengia is the largest of the eight major urdefhan walled cities in Doga-Delloth, one of the vaults of Orv. It is the northernmost city on the vault's Sightless Sea coast, and stone piers extend out into the sea.
It is a city of towers and spires carved out of black basalt. There are glowing domes, as well as rookeries for the skaveling mounts used by the urdefhan. There are also numerous statues of the daemons worshipped by the urdefhans. Niovengia is ruled by Malefactor Tryfilion, whose position is sealed by the Misery Gage, an artifact gifted by his patron Trelmarixian.