Archaeological excavations proved that the Visoko Valley was the center of a medieval Bosnian state and later kingdom. Many royal charters were written in Visoko and surrounding locations. Visoko Valley, as it is called today, included old royal town Visoki, its trade center Podvisoki, Mile, coronation and burial place for Bosnian bans and kings, and area of Moštre, where Bosnian Church institutions were located, including a university.
The royal town of Visoki was a fortress which existed during the time of the medieval Bosnian state. The first mention of the town happened on 1 September 1355, but it is believed to have been built even earlier. It was used by Bosnian bans and kings as a ruler's residence from which several official charters were written to other states. It was also defensively fortified, as the fortress had a trench and many towers of varying sizes. Visoki was first mentioned in a charter written in the royal town of Visoki, and was named in castro nosto Visoka vocatum. The charter was written by a young ban, Tvrtko I of Bosnia, who later became king in 1377 by his coronation in Mile. Several other rulers and nobles wrote charters in Visoki, including King Stephen Ostoja of Bosnia and Tvrtko Borovinić, who would be the last to write of the old town of Visoki in 1436 in the document on Visoki.
Visoki was built on Visočica hill, at a height of 766 meters, and 300 meters above the valley where the modern town of Visoko is located. By the time of the Turkish conquest of Bosnia, the old town was probably destroyed and never reconstructed. Few remnants of old Visoki remain, most being preserved in the town's museum. In situ evidence include the remains of foundations of the towers, walls and gates of Visoki. A model has been reconstructed according to plans of Đoko Mazalić made in 1953. The old royal town of Visoki is a national monument of Bosnia and Herzegovina. Today, beginning from 2007 its ruins are being slowly excavated so the town is becoming visible more and more.