Mount Hakurei

Mount Hakurei (Hakurei-Zan) was once a sacred mountain of absolute purity and divinity. Beautiful flowers skimmed the surface, from the earth to the mountain formation itself, a place where no demon dared to enter. This served as the battleground for the one of the most prominent battles of the Inuyasha franchise.

A once revered and great monk fell into despair upon attempting to reach nirvana and became a living Buddha as he died. In his misery, Naraku approached him and tempted him to the darkness. Manipulating him in his vulnerable state, the monk agreed to help him, and with his new powers, was able to manifest a nigh-impenetrable barrier that could ward off demons. Naraku uses Mount Hakurei as his new base of operations while he constructed a more powerful body.

Destruction
After Kikyo convinced St. Hakusein to release the barrier, Naraku's miasma corrupted the mountain turning it's vegetation rich state into a state in which it appeared as a barren wasteland. Afterwards, demons stared to emerge from the caves that were unaffected by the barrier. Then after that, when battling InuYasha and Koga, with a singal attack he destroyed the mountain of purity.

In later chapters
Later on in the story Naraku goes here to reabsorb Onigumo's heart, hoping to make sure Kikyo can't purify the Shikon no Tama because of Onigumo's negative feelings.