Hlavné námestie means Great Square in Slovak, but the early history of this city and its central square is tied to the German colonists who arrived here in the mid-13th century, at the invitation of King Béla IV of Hungary. The city of Košice (Kaschau in German, Kassa in Hungarian, and Cașovia in the old Romanian chronicles), existed at the crossroads of great trade routes linking the Baltic Sea with the Black Sea; Poland with Transylvania; the east of Europe with the south of Europe. Its urban space is rigorously structured. Three parallel roads run from north to south, with the middle road becoming progressively wider until it meets the main east-west artery, forming a special, lens-shaped square. The lens shape is due to the construction of the square in a region that formerly functioned as a trade fair. The trade fair took place in a widened section of the road, halfway between a castle and an abbey, before any other buildings were constructed. The shape also comes from the unification, through a typical process of a synoecism, of two distinct pre-13th century settlements, whose borders were those of the present-day square. At its centre, where these two axes intersect, the German colonists erected a parish church. In the 14th century this church was replaced by the Gothic Cathedral of Saint Elisabeth, the largest Cathedral in Slovakia to this day. The tower of Saint Urban, containing a seven tonne bell, and the Chapel of Saint Michael, both Gothic and built in the 14th century, flank the Cathedral, creating a unique and unitary whole. The theatre, a Neo-Baroque jewel, was finalised in 1899. Gothic houses, Renaissance and Baroque palaces, and Art Nouveau buildings define the perimeter of the square. The contours of the old city walls are clearly visible along the circular paths of the adjacent streets. The lens-shaped square of Košice is the largest and most coherent urban ensemble of its kind, typical of eastern Slovakia.