The Main Square of Maribor, also known as Glavni trg, is a square in Maribor, the second largest city in Slovenia, situated in the northeast of the country. On 17 November 1929 the aircraft: Raab-Katzenstein KL.1 Schwalbe with registration: D-974 crashed on Main Square of Maribor, with the death of Letalski center Maribor secretary: Ivo à  estan and the factory pilot Hans Müller. It used to be home to Maribor Slovenia's merchants' and on the upper side of the square is home to an open market.