In 1655 Olomouc was declared a fortress town. A baroque fortress was gradually raised and its construction was completed by the so-called Theresian fortifications erected between the years 1742-1756. Olomouc became one of the largest and most sophisticated star forts not only in Bohemia, but also throughout the Habsburg monarchy. The fortress was tested in a crucible soon after its completion, when it withstood a five-week siege by Prussian troops in 1758. During a city tour, admirers of military monuments shouldn’t miss the unique Theresian gate dating from 1752-1753, whose architectural design is based on the ancient Roman triumphal arch. It is the only preserved fortress gate still standing on its original location. The monumental Theresian Armoury, a typical example of Theresian military architecture, is worth seeing as well.

But even the construction of a baroque fort did not put an end to the fortification story of the city. By the middle of the 19th century bastion walls of the town center were completed by a crown of advanced forts (e.g. Fort Křelov), which moved the main defense line further into the foreland. During the 19th century many such forts (e.g. Fort Radíkov) were built and Olomouc became a unique example of this kind of fortification in our country. City visitors can now visit the Fort No.XIII in Olomouc – Nová Street and Fort No.XVII in Olomouc - Křelov. However, because the walls hindered further development of the city, the fortification function of the city was abandoned by the end of the 19th century.