P'Li's prison

P' Li's Prison is a special prison located in the Northern Water Tribe. To ensure the powerful firbender did not escape the prison cell she is in is located under the surface and the prison is coverd in ice and very cold so she has no heat to draw energy from inorder to firbend.

History
In 171 AG, following Harmonic Convergence, Zuko learned of the escape of the criminals Zaheer, Ming-Hua, and Ghazan from their custody under White Lotus sentries, and was particularly disturbed to hear that Zaheer had become an airbender.[26]  After warning Lin Beifong of their escape, he traveled with Chief Tonraq to the Northern Water Tribe, where they met with Desna and Eska, the new Northern chiefs. Together, they went to the prison of another criminal and ally of the escaped fugitives, P' Li, in order to secure it. While riding the elevator to the prison area, Zuko explained that P'Li possessed the ability to create explosions with her mind, and casually remarked that ironically he once sent an assassin with similar abilities to kill the Avatar, but that it didn't work. Eska shared with Zuko her own experience trying to assassinate the Avatar after the latter spoiled her wedding. When they finally reached the cell, P'Li quickly ascertained that Zaheer had escaped since she hadn't had any interesting visitors for thirteen years.