Azati Prime was the main planet in the Azati Prime planetary system. This was one of two worlds colonized by the Xindi in that system. The planet was mostly covered by water, with the few small landmasses not containing any life. All of the Xindi facilities on Azati Prime were located underwater - this included the construction yards for the Xindi superweapon.
Degra visited this planet shortly before traveling to the Calindra system to test a prototype of the Xindi superweapon in December 2153. (ENT: "Stratagem")
In February of 2154, Enterprise located the weapon on Azati Prime. Once the Xindi realized the Humans knew where the weapon was, they relocated it to the Xindi Council planet. (ENT: "Azati Prime")