Sto Lat is both a town on a hill overlooking the Sto Plains, and a kingdom rules by Queen Kelirehanna. As  such it also controls Sto Helit which issues its own stamps, Sto Kerrig, and the Long Thin Debated Piece Hubwards of Sto Kerrig. In fact eight protectorates are mentioned, but I do not think all are specified in the books. It first appeared during the events in Mort.

It was an early adopted of Discworld stamps during the Year of the Signifying Frog, quite probably due to Moist von Lipwig and his iconic Ride to Sto Lat, which probably saved the AMPO in the early days of its reformation.
 â€¦ er, it doesn`t seem right, licking ….. well licking Ankh Morpork stamps. Couldn’t you print up a few for us? We’ve got a Queen, nice girl. She’d look good on a stamp. We’re an important city, you know! So said the Mayor of Sto Lat.

It is home to Apslys Commercial Bank which features in both Going Postal and Making Money.

Dont forget to send a post card home