The Seventh District is the location of a faction of the Resistance established in Akolan, a city of slave rabbits in the High Bleaks. It has been led by a series of rulers, all known by the title of the Tunneler and is encompassed within the Lepers' District, as a way of concealing and protecting the entrance from the Wrongtreaders.
Rather than being a main residence for anyone of the Resistance (besides the Tunneler), the Seventh District seemed to serve as a meeting place and center of discussion and labor for the freedom of the Resistance in Akolan.
The Seventh District was founded by the first Tunneler, who was taken captive by the Lords of Prey from the deck of the ship Vanguard during the Battle of Ayman Lake. A number of other Tunnelers succeeded him, building on the efforts of their predecessors. Presumably, the name of the Seventh District came about after the other six districts of Akolan had been established.