In Jainism, Sammed Shikharji (also called Shikharji) is considered the most sacred place for dhyaan (meditation) and liberation because:

• It is believed to be the place where many Tirthankaras performed intense ascetic practices and achieved keval-jnana (omniscience) and moksha (liberation). The environment is described as highly sattvik (pure) and conducive to deep spiritual effort.
• Historically, Tirthankaras choose remote, austere places for long tapasya. Sammed Shikharji is seen as a perfect setting for such austerities, so many Tirthankaras are said to have attained moksha there.
• The site is revered as a collective spiritual milestone: it is traditionally held that a large number of Tirthankaras attained moksha from this single, sacred hill, which reinforces its significance as a place of ultimate release.

Notes on tradition:

• Different Jain traditions (Digambar and Shwetambar) may emphasize slightly different narratives about which Tirthankaras attained moksha there and the exact details of their tapasya. Both agree on Shikharji’s exceptional sanctity and its importance as a place for intense spiritual practice.

If you’d like, I can provide the exact verses or citations from Digambar and Shwetambar texts that describe Shikharji and the Tirthankaras associated with it.