Indrakīla (Indrakila) was a parvatatīrtha (parvatatirtha, a mountain-based site of pilgrimage) in Bhāratavaṛṣa (Bharatavarsha or India). Kubera was the ruler of this mountain, located near the mountain Gandhamādana (Gandhamadana). Arjuna came here during his exile in forest, and here he had a vision of Indra, king of the gods, disguised as a tapasvī (tapaswi, asectic). Here, on this mountain, Indra promised Arjuna to give him the divine weapons. Again in this Indrakīla (Indrakila) mountain, Arjuna engaged in a duel with Mahādeva (Mahadeva or Lord Siva) who was disguised as a hunter. But in the commentary by Haridāsa Siddhāntavāgīśa (Haridasa Siddhantavagisa), ‘Nīlameghasamaprabhaḥ’ is written in place of ‘Indrakīlasamaprabhaḥ’. Perhaps the word, ‘Nīlameghasamaprabhah’ is used as an adjective to describe the Indrakīla (Indrakila) mountain. But in his edited version, Siddhāntavāgīśa (Siddhantavagisa) uses the adjective as a noun.

The scholars think that the ancient name of the present state of Sikkim was Indrakīla (Indrakila) or the garden of Indra. As Sikkim is surrounded by the Himalaya mountain, it is possible that Sikkim is connected in some way with the ancient Indrakīla (Indrakila).[G. P. Singh; Researches into the History and Civilization of the Kiraatas; p. 86].