- You may also be looking for Delta Triangle.
Map of The Triangle
The Triangle is an area of space between the United Federation of Planets, the Klingon Empire and the Romulan Star Empire. (FASA)
The popular nickname of the region is a misnomer as, astrographically, it's only a triangle in cross section, looking "down" from "above" the plane of the galaxy. Its true shape in three dimensions is more that of an hourglass with a roughly triangular cross-section.
22nd century[]
The first major wave of settlements in the Triangle was in 2172. (Star Trek: Avenger, modified from FASA RPG materials)
23rd century[]
Nimbus III was located within the Triangle. (Orion Press: Liberation from Hell)
In 2275, Gibraltar -- an unwanted world situated between the Federation and the Romulan Star Empire -- becomes one of the most important in the Triangle when the two governments choose it as the site for negotiating a settlement. Also, during that year, Klingons occupy the Triangle world of Marram IX. (FASA RPG)
Shadowstar Station's construction was authorized by the Federation Council's Military Staff Committee in 2286. The station's primary raison d’être was to serve as primary customs house for commercial traffic in and out of Triangle space. (Star Trek: Shadowstar Station)
Following the Khitomer Accords of 2293, the Federation expanded its territories into the Triangle as the New Colonies. Starbase 52 was constructed as the liaison facility between the New Colonies and the Federation heartworlds. (Star Trek: Accord)
24th century[]
Starbase 77 was in operation by 2308. (Federation Shiplist - Starbase Fifty-Two)
Later in the 24th century, Unity One Starbase was built at the heart of the Triangle. (Star Trek: Unity)