Deneva

Deneva, also known as Deneva Prime, was the inhabited prime planet orbiting the primary, in the Alpha Quadrant. The planet was affiliated with the United Federation of Planets. By the 2260s, the Human citizens of this planet were called Denevans.

The Deneva colony was established on this planet in the mid-22nd century. This planet was, also, the location of the Deneva Station. The reason for colonization was that the planet would serve as a freighting-line base in the sector. Supplies would be sent to the miners in the system's asteroid belt and what was mined in the asteroids would be sent back to Deneva for transfer to other Earth, and later Federation, worlds and colonies. Deneva was considered one of the most beautiful worlds in the galaxy. In 2267, there were over a million inhabitants on this world, with more than a hundred thousand living in the capital city alone. The nearest starbase was Starbase 10. 

Earth Cargo Service vessels were making runs to the colony as early as 2153. 

Its geothermic grottoes were mentioned by Sub-Commander T'Pol as being similar to that of Dakala, a rogue planet discovered by the crew of in 2151. 

Leland conducted an away mission to Deneva that unfortunately involved the wrong ambassador.

Gabrielle Burnham told Christopher Pike that Deneva was one of the devastated worlds that she visited in the 33rd century. 

Montgomery Scott worked in this freighting line as an engineering adviser early in his career. He was on a couple of runs.

In late 2266 – eight months before the visit of the USS Enterprise (NCC-1701) – space vessels from Ingraham B brought an infestation of flying parasites. These parasites would have wiped out the colony, as they had Ingraham B and at least three other civilized worlds, had not Kirk and his crew destroyed them. Many people died from the infestation, including Kirk's brother Sam, just before the arrival of the Enterprise, and his wife Aurelan, soon after. The couple had moved to the planet with their son Peter not long before the infestation. 

Denevan crystals apparently originated from the planet. 

Background information
The city exteriors for Deneva were shot on location at the TRW Space and Defense Park in Redondo Beach, near Los Angeles. Filming took place on Wednesday. The establishing shot of Kirk's brother's lab was a building on the campus of UCLA, and the entrance to the building was the cafeteria at TRW. (These Are the Voyages: TOS Season One)

According to StarTrek.com, Deneva was an M-class planet.

According to Star Trek Maps, Deneva was the third planet in its system.

According to the RPG sourcebook The Federation, Deneva was the fourth planet in the Beta Darius system.

According to Star Trek: Star Charts (pp. 36, 45, "United Federation of Planets I") and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), in 2120, Zefram Cochrane visited this planet on his final voyage. In the mid-22nd century, Deneva was a destination on a Vulcan trade route. In 2378, Deneva was a Federation member.

Deneva, the primary of Deneva, was located in the Alpha Quadrant on a star chart seen in the episode.

Apocrypha
Deneva was one of many worlds destroyed in the Borg invasion in Star Trek: Destiny: Lost Souls.