A little hard to find at just a few feet north of 97th St. on Park Avenue, Earl's is worth finding.
Combine it with a trip to Museum of the City of New York, El Museo del Barrio, upper Central Park and the Conservatory Garden, the Jewish Museum, Cooper Hewitt Smithsonian Design Museum, or the Guggenheim, all on or just off Fifth Ave, and you'll have a fine outing. The subway runs up Lexington.
Earl's is an interesting little neighborhood spot, with delicious sandwiches and soup, that earned a favorable review in The New Yorker when it first opened. Besides, they are friends of ours!