The Earth research centre where Henry Archer's warp five engine was developed and the NX test programme was run, paving the way for Enterprise NX-01.
The Warp Five Complex is the facility on Earth where humanity's first engine capable of warp five was designed and built. The work was led by Henry Archer, father of Jonathan Archer, and continued for decades after Zefram Cochrane dedicated the site.
Footage of that dedication, with Cochrane speaking words later echoed in Starfleet's mission statement, is shown in the Enterprise pilot Broken Bow, where childhood flashbacks also show Jonathan with his father as the project takes shape.
The episode First Flight looks back to the NX test programme of 2143. Archer and his rival A.G. Robinson compete to break the warp two barrier, and after the NX-Alpha is lost and the Vulcans press for a halt, the two steal the NX-Beta to prove that the engine works.