Ishtar Gate
From Tardis Wiki, the free Doctor Who reference
The Ishtar Gate was an entrance to the city of Babylon. It consisted of large bronze-plated cedar doors, guarded by bronze statues of dragons and bulls. As armies were not allowed in the holy city, passing through the gate meant passing from the lands of war to lands of love and peace. In other words, one passed between the two domains of Ishtar through this gate.
In 323 BC, the First Doctor, Barbara Wright, Susan, and Ian visited the gate on their visit to Babylon, having materialised in the Hanging Gardens within the walls. (AUDIO: Farewell, Great Macedon)
