The Jagd Yensa is a region in the land of Ivalice in Final Fantasy XII, located to the west of Dalmasca. It is Jagd territory, and thus airships cannot travel over it. The entire region is covered in a vast desert.
The Yensan Sandseas
The Yensan Sandseas consist of the Ogir-Yensa Sandsea and Nam-Yensa Sandsea. The sand behaves like water, the local Urutan-Yensa attack other races on sight, and abandoned oil fields can be found in these areas.
The Tomb of Raithwall
The tomb of the Dynast King Raithwall himself. The tomb is full of traps, which will activate if intruders don't have proof of royal heritage. Deep within lies the Dawn Shard, as well as the Dynast King's treasure, the Esper Belias.
The Zertinan Caverns
A vast network of caves connects the Westersand and the Sandseas, then goes under the inland sea between the Ordalian and Kerwon Continents, reaching even the Ozmone Plain in the region of Balfour in Ordalia. Rich in loot, but also rich in tough fiends. Deep within the caverns sleeps the Esper, Adrammelech, the Wroth.