[1] The territory of the Yakshas under the kingship of Kubera is described in the Mahabharata as being the region surrounding the Kailasa mountains and Manasa lake in the Tibetan Himalayas.
Regarding the expeditions of the Pandavas guided by sage Lomasa, we are told (in the Mahabharata 3:139): Section 3:152 describes Pandava Bhima's expedition to the Yaksha territory: Bhima saw in the vicinity of the Kailasa cliff, that beautiful lotus lake surrounded by lovely woods, and guarded by the Rakshasas.
Beholding the Rishi arrived there, all the Rakshasas having Manibhadra for their head, who were engaged in protecting that lake abounding with beautiful lotuses, came out in a body for welcoming and honouring the illustrious traveller.
Here are many plains covered with grassy verdure, as also the plantain forest, and those celestial trees called the Sautanakas.
Here, in this quarter, at a place called Usiravija, by the side of the golden lake, king Marutta performed,a sacrifice.
The region, called Mandakini, of king Vaisravana is attained by those highly blessed persons for whom are every joy and comfort.
The spot where Ganga rusheth past, cleaving the foremost of mountains which is frequented by Gandharvas and Yakshas and Rakshasas and Apsaras, and inhabited by hunters, and Kinnaras, is called Gangadwara (3:90).
Delicious and cooling breezes murmuring through forests of tall Mandaras, and bearing fragrance of extensive plantations of jasmine, as also of the lotuses on the bosom of the river Alaka and of the Nandana-gardens, always minister to the pleasure of the King of the Yakshas.
The banks of river Narmada are described as the birthplace of Yaksha king Kuvera (Vaisravana), where his father Visravas, who was a sage, lived (MBh 3,89).
That adorable Being, leaving Lanka and followed by Gandharvas, Yakshas, Rakshasas, and Kinnaras, went to live on mount Gandhamadana (near Kailasa, Tibet).
The lord Kuvera of body resembling pure gold, seated in his car of great splendor, and accompanied by numerous Yakshas came there.
And within it stood a mansion with high walls and a gateway, plastered over with powdered earth, and rich with smoke bearing the fragrance of fried paddy.
Entering that mansion, Sikhandini, the daughter of Drupada, began to reduce herself by foregoing all food for many days.