Nanda Parbat is the home of Rama Kushna, the one who gave Deadman his power. This place is also believed to be the home of Green Lantern Kai-Ro. It figured heavily into the story arc 52 as it focused on numerous characters visiting there including Ralph Dibny, Renee Montoya and Vic Sage.
Within the walls of Nanda Parbat, time passes differently. While its inhabitants may experience decades, they will continue to retain their youth, and when venturing outside again, they will find that less time has past. As Renee Montoya put it: "Time stands still in Nanda Parbat. Days, weeks, months... I can't tell. Life is defined by routines, not time." Though most of the citizens who live in Nanda Parbat are monks in service of Rama Kushna, its walls are also made home to those who come wishing to find peace and enlightenment.