The San Remo was a bar at 93 MacDougal St. at the corner of Bleecker. In its heyday it was across from the Café Borgia and the Figaro. Big destination corner.
Now 93 MacDougal is a crappy chain coffee store.
It was a hangout for folks like... well, look on the plaque. Now, not so much.
Jack Kerouac described the bar's crowd in his novel The Subterraneans, which is based in large part on the San Remo:
Hip without being slick, intelligent without being corny, they are intellectual as hell and know all about (Ezra) Pound without being pretentious or saying too much about it. They are very quiet, they are very Christlike.
Save the Village indeed. If it is not already too late.
Dylan's song Subterranean Homesick Blues also is derivative of the place. Take one of the Save the Village tours and learn more. And have fun doing it.