The Gleb Jungle was a location on the planet Ferenginar. It remained undeveloped for years, despite several attempts to build on the marshland, all of which failed. This left the jungle untouched and overgrown into the 24th century.
A secret crawlway connected the home of Nog's maternal grandfather, Dav, and a secret hatchway buried in the Gleb Jungle. Thisw had been built by one of the home's previous owners, as a way of escaping his creditors in case of bad times. (DS9 - Worlds of Star Trek: Deep Space Nine novel: Ferenginar: Satisfaction is Not Guaranteed)