A new underground station at Střížkov in Prague has been designed and built as a special structure with a high level of aesthetics. The hall structure is 160 m long, 42 m wide and 20 m high. Two crossing hingeless main arches spanning 160 m are fixed to concrete pylons. The roof structure is suspended from the main arches using a system of prestressed rods and supported by columns around the roof. Most of the members are curved with variable cross-sections (the majority of sections are welded boxes with a plate thickness of 10 - 35 mm except the columns, which are welded I-sections). The geometry of all parts made design, fabrication and erection very difficult. The whole structure was built under the direct supervision of the architect. The underground station was opened to the public in May 2008.