Falkreath is a smaller town situated in the south of Skyrim. It was once considered part of Cyrodiil, and the two countries have warred over it throughout the years, but currently it is under Skyrim's borders. There is no castle in Falkreath, and so the Jarl resides in a Longhouse at the head of the town.
One of the main defining 'attractions' of Falkreath, is it's large, ancient cemetary; due to this, a lot of the buildings here have somewhat morbid names: Corpselight Farm, the Grave Conction, Dead Man's Drink etc.
The Dark Brotherhood has its main Skyrim sanctuary a short distance away from Falkreath.