Omphalos

—Rather bleak in wintertime, I should say. Martello you call it? —Billy Pitt had them built, Buck Mulligan said, when the French were on the sea. But ours is the omphalos.

Source: wiktionary

Here I was, embosomed in the very nave, the very omphalos of furtive femininity—a prize patron of the women's restaurant, a member, privy to its innermost secrets.

Source: wiktionary

The place in which this statue stood, Malalas writes, was called “the omphalos of the city.”

Source: wiktionary