Masov Oasis, sometimes simply referred to as Masov, is a settlement in the Uldt Desert on Carrow, a jointly settled world inhabited by Sangheili and humans. The settlement is located in Sangheili territory, though Masov Oasis is commonly frequented by human traders.
By July 2558, Masov Oasis had fallen under the control of Thars 'Sarov, an anti-human Sangheili leader on Carrow. Thars' followers captured the human traders that frequented the settlement and locked them in a Sangheili building. Around this time, Dahlia from Sandholm ventured to Masov Oasis in desperate need of medicine after her own settlement fell victim to disease. However, upon arriving at Masov, Dahlia was captured and locked away with the human traders. Dahlia and the traders were eventually rescued by Jat, a Sangheili opposed to Thars' rule.
Located south of the Astlehich River in the vast Uldt Desert, Masov Oasis is an island of buildings. Masov Oasis is one of the few oases remaining on Carrow's main landmass. As such, a settlement was built upon the oasis, as every greenspot on the planet is considered rare and precious. Masov Oasis is located halfway between Sandholm and Rak, seventy kilometers from each, with Sandholm to the south and Rak to the north of the oasis.
The buildings of Masov Oasis are mostly Sangheili in design; tall spires among the trees and domes scattered across the settlement's handful of streets, all lit by floodlights. Masov is home to bubbling fountains, clean buildings, and carefully maintained gardens, and was described as serene and peaceful at night. The human traders that frequented Masov gathered in a square, metallic two-storied building that stood out among the rounded buildings built by the Sangheili.