Due to its location in central Berlin, with its many shops, offices, official buildings, embassies, hotels, as well as cultural and entertainment (Friedrichstadtpalast, Metropol theatre house, opera house, Museum Island), as well as being a border checkpoint, traffic in the station was enormous. In the beginning after the wall had been built, both the eastbound and the westbound border traffic was controlled on ground level. These rather constrained circumstances, compounded by the traffic in and around the station, led to the construction of a building on the square north of the station, which was connected to the main station. This new building was used for westbound border crossings, with separate checkpoints for West Berliners, West Germans, foreigners and diplomats, transit travellers, and the small number of East Germans with exit visas. On the door was a guard station to separate people permitted to cross the border from those ineligible, leading to many tearful goodbyes in front of the building. This gave the building the moniker "Tränenpalast" ("Palace of Tears").