Train station, in particular a tunnel-type train station, and use of a filter unit in a train station

A train station comprising:

• at least one transportation route for traffic of vehicles, wherein the at least one transportation route comprises a vehicle tunnel;
• at least one public waiting area arranged adjacent to the at least one transportation route;
• an enclosure that partially encloses the at least one public waiting area and the at least one transportation route, wherein the enclosure comprises at least one side wall;
• at least one ambient air purification arrangement configured to purify ambient air and comprising one or more filter units configured to separate solid, liquid or gaseous ambient air pollutants from the ambient air;
• wherein the one or more filter units are arranged at and/or in the at least one side wall of the enclosure, wherein the at least one side wall of the enclosure comprises a curvature viewed in a plane positioned normal to a length extension of the at least one transportation route, and wherein the one or more filter units comprise a curvature corresponding to the curvature of the at least one side wall of the enclosure.