omphalos

a thing or place that is of greatest importance to an activity or interest during the Vietnam War the university's campus effectively became the area's omphalos for antiwar activity Synonyms axis, base, capital, central, core, cynosure, epicenter, eye, focus, ground zero, heart, hub, locus, mecca, navel, nerve center, nexus, nucleus, center, seatRelated Words headquarters; happy hunting ground, hive, hotbed, hot spot, playground, playland; kernel, nub, pith; deep, thick; essence, quintessence, soul; attraction, lodestone (also loadstone), magnet, polestar