Tyrsis is the largest city in the Borderlands and the capital of the Callahorn. It is a fortress city that has never fallen to an invading army, although its walls were breached once by the armies of the Warlock Lord due to treachery. It is home to the legendary Border Legion, the army that protects the Callahorn from frequent Gnome raids as well as attempts by the Federation to annex the region.

Notable features of the city include People's Park, situated in front of the palace where Kings of Callahorn used to rule. The Sword of Shannara was housed in the Park for centuries after Shea Ohmsford had used it to defeat the Warlock Lord. Much of Shea and his company's adventures took place in and around Tyrsis.

During the time of Federation control of the Southland, Tyrsis is occupied by the Federation and a new People's Park is built over the original park, where the Sword of Shannara is still kept. The Federation took control of Tyrsis at the same time that they made the Callahorn a "protectorate." It was during this time that Par Ohmsford and his brother Coll took the Sword of Shannara from the Park with the aid of people in the Free-born Resistance, including Padishar Creel and Damson Rhee.

Centuries later, Tyrsis and Callahorn are free from Federation control and are protected by the Free-born, but they must once again do battle against the Federation on the Prekkendorran Heights. They are aided in their efforts by the Elves.