Sri Aurobindo translates Katha Upanishad, Second Cycle: Second Chapter, Verse 1: “Yama speaks: ‘The unborn who is not devious-minded has a city with eleven gates: when he takes up his abode in it, he grieves not, but when he is set free from it, that is his deliverance. This is That thou seekest.”
The divine Presence takes on forms, including the human form, to manifest Spirit in Matter. In the human being this Presence has developed an instrument of action that includes the physical body, the vital-nervous sheath which carries the sense perceptions and impulses to action, and the mind. The Divine does not suffer from this embodiment. While appearing to be bound, He is always free. When He recognises His freedom, he is able to act from the divine standpoint rather than from the limited human standpoint.
The city with eleven gates has been defined variously by historical commentators. Some commentators indicate this refers to the physical body and that the eleven gates are the 2 eyes, 2 ears, 2 nostrils, mouth, the anus, the genitalia, the navel and the crown of the head. The crown of the head is the location where the soul exits the body at the time of death. Other commentators indicate that the city with eleven gates refers to the 5 senses of perception, the 5 senses of action, and the mind. Based on the usual starting point for the link between the Purusha and the embodiment in the world, it is likely that the first reading is the intended one, and it is by far the one most often described in the commentaries. The body is a vehicle for the soul in the world and is the way we identify ourselves in our lives, first and foremost.
Sri Aurobindo, The Upanishads, Katha Upanishad, pp. 213-241, and Kapali Sastry, Lights on the Upanishads, pp. 104-129