The deserts surrounding Umajo-Kenta are larger than all of Maini. The heat in the desert is so intensive that to survive there for long without getting dangerously exhausted, people need to use a special liquid porenoil that can be obtained from Umajo-Kenta. Another hazard are the sand divers, strange animals shaped like insect larvae, which emerge from the sand and attack by throwing rocks. It's also quite possible and potentially dangerous to simply get lost.
The desert contains mainly sand, but at places it is also littered with strange rock formations. A secret way between these leads to an underground passage that can be used to reach yet another large area of desert.
The Umajo have built their prison far in the desert, though they recommend it as a place for visitors to see for some reason. A guard goes there every day around noon and can act as a guide. It's recommended to carry extra rations and Porenoil from Merdger while making this trip through the desert.