Azure Nebula
From FEInfobase
The Azure Nebula is a class 11 nebula that was located on the former border between the Federation and Klingon Empire. There had been several skirmishes between the two powers here, the most noted one was between Captain Sulu’s USS Excelsior and the Klingon battle cruiser commanded by Captain Kang in twenty two ninety three.
The nebula was filled with oxygen and argon with trace amounts of thetazenon, flourine, and sirillium.
In 2404 the USS Enterprise-F visited the nebula in attempts to make diplomatic contact with a Klingon armada that had been discovered in the nebula from Starbase 18. It was believed the armada was preparing for an invasion against the Archer System. Fleet Captain Zack Marshall-Bennet, Commander T'Val and Lieutenant Moran met with Klingon General Lavok and discussed the possibilities of ending current hostilities. However the meeting ended and the Klingons launched their fleet from the nebula against Archer IV (ENT-F: "A Good Day To Die").