Semarang's most famous landmark Lawang Sewu ('Thousand Doors') is actually two colossal colonial buildings that were once one of the headquarters of the Indonesian railways during the Dutch era. Some renovation has recently been completed but most of the main L-shaped structure remains closed to visitors. Nevertheless, you can wander the empty corridors of the other huge building, where clerks and engineers once worked, and admire the features (including some magnificent stained glass and marble staircases).
The building is regarded as a haunted house by locals; during WWII the Japanese occupied the building and used the dungeons for interrogation. You can tour the flooded basement on a guided tour (not always available in English), see where many lost their lives and hear the gruesome tales of the atrocities that were committed here. It's a deeply moving experience, particularly at night.
