The city was long ago destroyed and fell into ruin, and it is now the site of Skavenblight.
There is some evidence to suggest that Tileans and Estalians may be fully or partially descended from former inhabitants of Tylos or the lands surrounding it.
Most information about the city is shrouded in myth.
One common Tilean tale called The Doom of Kavzar states that the city was destroyed after they constructed a large tower, and a stranger offered to complete it and crown it with a huge bell. When the bell rang out 13 times, rain fell constantly and rats roamed the streets. Eventually the Dwarfs disapeared, and the people of Tylos fled. See the page on Skaven: The Doom of Kavzar to read the story in full.
Another version of the myth that it was Myrmidia who comissioned the city, and Tylos was the name of it's mortal founder. After Tylos began building a pointlessly large tower, Myrmidia abandoned the city. When the city fell to dark powers, Myrmidia returned and led the fleeing people of Tylos away to safety in the east and west. See the page on the Cult of Myrmidia to read this version in full.
The myths date the city back to the time when High Elves still colonised parts of the Old World.