At the lowest level, there are three groups of underground platforms. The most southerly are terminal tracks 21 and 22, with a single island platform, and accessible only to trains on the SZU's Uetliberg and Sihltal lines. To the north of these are two island platforms serving tracks 31 to 34, known as the Löwenstrasse station, which link to the station's western rail approaches, and to an eastern approach via the Weinberg tunnel from Oerlikon station. Some distance to the north of these are two further island platforms serving tracks 41 to 44, known as the Museumstrasse station, which also link to the station's western approaches, and to an eastern approach via the Hirschengraben Tunnel from Stadelhofen station.