Update: The 'Reisebüro' sign mentioned here has, unfortunately, been removed, and there's no longer the Sharp advertisement on the front either!
If you've been to Alexanderplatz, you'll probably have noticed the building with the big flashing neon Sharp Aquos advertisement on it.
Of course the building actually has nothing to do with the Japanese electronics firm. A quick peek round the back reveals a clue to its history...
The sign says 'Reisebüro' - which could translate as travel agent's. It's not a new sign, either; in fact, I'm fairly sure that if you were to take the neon sign off the front of the building, you'd find an identical 'Reisebüro' sign underneath (only I wouldn't recommend doing that, unless you also want to find out what the inside of a Berlin jail looks like).
This building is the Haus des Reisens (usually literally translated as 'house of travel' though I think a case could be made for translating it as 'travel building'). The travel agency it housed wasn't just any old travel agency: it was the travel agent. The "Reisebüro der DDR", the GDR's state travel bureau, to be more precise.
The Reisebüro der DDR (which, until 1964, was known as the Deutsches Reisebüro - German Travel Bureau) had branches in cities across East Germany; this was its main office. That wasn't all, though - the Haus des Reisens was conceived as a kind of one stop shop for everything travel-related.
A booking office for East Germany's airline, Interflug, could be found here too, along with also a police registration office for foreigners, a foreigners' advice centre, a bureau de change of the Industrie- und Handelsbank (Industry and Trade Bank) and the tariff office of the ministry of transportation.
The Reisebüro der DDR offered organised tours to other socialist countries, as well as running hotels within the GDR, offering bookings for flights and train tickets and providing various services to foreign travelers in the GDR.
The building itself was designed by Roland Korn, Johannes Briske and Roland Steiger, with interiors by Hans Bogatzky. Korn was due to leave the GDR for Baghdad, to work as chief architect of Iraq, when plans by his collective won the competition for the redevelopment of Alexanderplatz and he was ordered to stay. The Haus des Reisens was built between 1969 and 1971 as part of this redevelopment plan.
The 17 storey tower block is surrounded by a two storey base, which has one of the building's most striking features - these unusual wave-like concrete mouldings, which are almost like the edges of a scallop shell. It's worth looking at in the satellitle pictures of Google Maps too - the scalloping's quite visible there and it looks almost more striking there than it does from the ground. The detailing provides an interesting contrast to the hard, skeletal lines of the tower block.
The eastern side of the building has a copper relief work by Walter Womacka. It's called "Der Mensch überwindet Zeit und Raum" (man overcomes/conquers time and space).
Womacka was a prolific artist in the GDR and his work is well represented around Alexanderplatz - the fountain in front of the Kaufhof department store (called the Brunnen der Völkerfreundschaft, which could be translated as 'fountain of friendship between nations') is also his work, as are the mosaics on the Haus des Lehrers (the building diagonally opposite the Haus des Reisens, over the other side of Karl Marx Allee).
If you like Socialist Realist art then this is really a fine example, brimming with space age optimism, which seems further enhanced by the building's sci-fi scalloping.
Perhaps the building's most talked about occupant now is the club Weekend which takes up two of the upper floors, and also opens up a terrace on the building's roof in the summer months. The Haus des Reisens may not be around for much longer, though: for some time now, plans have been in place to demolish it and replace it with a 150 metre tall skyscraper by Hans Kollhoff as part of his masterplan for Alexanderplatz, chosen in a 1993 competition. While not much currently seems to be happening in relation to those plans, the Haus des Reisens is currently far from fully occupied and, as it's not a listed building, it could well only be a matter of time before economic considerations bring its journey to an end.