Haupttelegrafenamt Berlin, Telegraph headquarters in Berlin-Mitte, Germany

The Haupttelegrafenamt Berlin is a four-wing complex in Berlin-Mitte, built in neo-baroque style and adapted to the street grid, so its wings are not exactly at right angles. The north wing on Oranienburger Straße is about 65 metres long, the south wing on Ziegelstraße about the same, while the east wing on Monbijoustraße is set back about 13 metres and is roughly 30 metres long. A central building connects the east and west wings.

Built 1910–1916 to designs by post building officer Wilhelm Walter with architect Max Lehmann, under site manager Hermann Streubel, it cost 3.1 million marks, the most expensive postal building in Germany at the time. It housed the latest telegraph technology and in its early years also directed the military radio station at Königs Wusterhausen and the Nauen transmitter. Full service began only in 1918, after the First World War.

The building's name lives on in the Hotel Telegraphenamt, opened in the Monbijoustrasse wing in 2022. In the basement, part of the pneumatic tube machine station was rebuilt and put on public display; other components went to the Museum für Kommunikation. The telegraph offices were organised by destination, one floor per target area in the east wing.

The complex fills the block between Oranienburger Straße 73–76, Monbijoustraße 7–15 and Ziegelstraße 20/21; the four wings meet at slightly non-right angles because they follow the existing street grid. The hotel occupies the side wing on Monbijoustraße, while the rest of the Forum an der Museumsinsel holds offices, shops and restaurants. A section of the preserved pneumatic-post machine station is displayed in the hotel area.

The basement contains remnants of the original pneumatic post system that once created a vast underground infrastructure beneath the city. This technical network allowed messages to be transported automatically through tubes before electricity transformed communication.