This is the door to Theseus's luxurious palace. It represents the financial and military power of the mighty duke. But it is not open to all. Symbolically, it is protected by a variety of Greek gods, those that you can see surrounding its door, specifically Athena, the patron goddess of Athens. It is further secured, though, by human guards, who assure that only nobles and the guests of Theseus will be allowed to enter. Be certain that if you are not a noble, you have permission before entering.