Parek Tonn was a fortress on ancient Bajor. The fortification was built into the face of Dahkur Province's Mount Kola.

In a vision Kira Nerys experienced, she and her Bajora forces planned to enter Parek Tonn, but found it inhabitated by the Eav'oq. The two groups later stood together in the fortress against the Ascendants. (DS9 novel: Warpath)

Parek Tonn also existed in the mirror universe. In 2375, Kira Nerys viewed a request to mine Mount Kola and also the objections to it. The objections concerned the belief the ruins of Parek Tonn would be destroyed by the process. (DS9 - Mirror Universe novel: Saturn's Children)

In his annotations for Warpath, David Mack commented "Parek Tonn is an invention of the author and former Star Trek books editor John J. Ordover. It was originally intended as an analog for the Hebrew fortress of Masada, in a Mack/Ordover spec teleplay for Star Trek: Deep Space Nine". [1]