Perhaps the most famous symbol and dominant of Opava, the town hall building with a typical tower known today as Hláska, fills the eastern space of Horní náměstí. The relatively complicated and rich history of this imaginary central point of the city seems to be reflected in the diverse and not always understandable names of the tower and the town hall itself. In the past, the names fluctuated between the German Turm, Stadtturm or Stadthausturm and the term Schmetterhaus for a house under a tower or Czech expressions such as Hláska, town tower or watch tower without a corresponding equivalent for the house itself.

In the first half of the 14th century, the city council underwent its southern tower at the parish church of the Assumption of the Virgin Mary in favor of the church. According to available information, a new tower was to be erected on the square in places where it probably already stood, or the so-called Schmetterhaus was built – probably a ground-floor rectangular building used for trade, especially for storing goods that were transported through the city. Later, a town hall building was to be built above the ground floor of the merchant’s chambers. The tower itself was used mainly to announce various events, whether it was the beginning of markets or fire. Under the tower stood a checkweigher for transporting goods. Major changes took place in the second half of the 16th century. While the town tower was swept away by the storm and waited fifty years for its new construction, the Schmetterhaus apparently underwent reconstruction after a fire in 1561.

The previous reconstruction of the old town hall building was subsequently supplemented in 1614–1618 by the construction of a new city clock tower, which was conducted in the Renaissance style by the builder Kryštof Prochhuber. The two-storey Schmetterhaus probably had a rectangular floor plan and was topped by an attic, the tower either stood in the façade or was introduced to the building. In addition to shops and bakeries, the first floor of the building was used in the second half of the 18th century to organize theater performances. In 1803, the building of the town guardhouse was added in front of the Schmetterhaus, and during this time one of several adaptations of the building took place. The first floor served as a residential area until the middle of the 19th century, later some of them were replaced by rooms of building and economic offices or a dwelling with a small cloak. Later, this floor served the calibration office, the military office, the Chamber of Commerce and Trade and its Museum of Applied Arts. On the ground floor, the abolished guardhouse was replaced by shops. At the end of the century, after the departure of the chamber and the museum, various offices were located here.

The city’s efforts to build a new building, which would have a dignified representative character and adequately complement the Renaissance tower, led to the announcement of a competition for the new Schmetterhaus at the very beginning of the 20th century. The winner of the total number of 82 submitted projects was Rudolf Srntz’s proposal. First, the demolition of the old building began in 1902, and during the following year, a new building was built around the tower in a historicist Renaissance concept. The three-storey building, consisting of three two-wing wings perpendicular to each other, is reinforced in the corners by bay windows. The main facade with associated windows and two balconies on the sides of the tower is provided with relief decoration – the emblem of the city carried by a pair of lions, coats of arms with jewels above the entrance and eagles on its sides or lions on the corner of the building. Lions and a pair of portrait medallions are placed on the attic of the side triangular shields. The prismatic tower, which retains its appearance from the beginning of the 17th century, ends with an octagonal superstructure with a gallery and a three-storey dome with two lanterns. The interior on the north side of the half-cylindrical staircase was used as a Niedermeyer café, and on the south side was the bank’s branch. The first floor served as living space and the second housed the city museum.

The building survived the next period without major changes, its appearance did not change even during the occupation, when an unrealized proposal was made to change the interior. Unlike the surrounding houses, Hláska survived the liberation of Opava without significant damage to the tower and the exterior masonry, and the roof on the north side, along with some burnt-out rooms, remained affected. However, some interiors suffered damage, especially the Niedermeyer café. After February 1948, the building housed the city’s national committee. The repairs during the following decades were only partial and did not change much about the appearance and the somewhat dull interior. The change was brought about by the overhaul of the building in the course of 2006. Extensive reconstruction, including the restoration of decorative and exterior elements, while respecting the original form from 1902, returned Hláska to a dignified appearance.