Gleisdreieck is an elevated Berlin U-Bahn station located on a viaduct in the Kreuzberg district, and served by lines U1, U2, and U3.

[2] The station's name literally means "railway triangle," or wye in English, and marks the spot of an earlier major train hub that opened in 1902, where the three branches of the first Stammstrecke U-Bahn line from Zoologischer Garten, Potsdamer Platz and Warschauer Brücke met.

After the building of the Berlin Wall beginning 13 August 1961, the lower platform became the eastern terminus of the U2, until service was finally discontinued on 1 January 1972.

This branch was protected only by signals, so that driver inattention could easily lead to a disaster, as happened on 26 September 1908.

Construction began in May 1912 to replace the triangular junction with two lines built as a grade-separated cross with a new Gleisdreieck interchange station at the intersection.