Keep your crusty titanium hull and your testy Basque separatists. Just a short jaunt up the New York Thruway from the Garden State sits the cracking crackerbox palace for minimal and post-minimal art that is Dia:Beacon. For decades, American exceptionalism in visual art revolved around Pollock, de Kooning, Rothko, Newman, and Kline. If it has taken ages to realize that Heizer, De Maria, Smithson, Serra, and Judd are as worthy, that’s in no small measure due to the fact that an institution must have loads of cash and acres of space to do them justice. At last, one does. Dia director Michael Govan will explain why Gehry’s Ballhaus in Bilbao is no longer the premier destination for museum-hopping art tourists when he delivers the 2003 Mordes Lecture in Contemporary Art, “Art and Its Surroundings: A Discussion of Dia Art Foundation’s New Museum at Beacon, New York, and the Art of the 1960s and 1970s,” at 3 p.m. at the Hirshhorn Museum and Sculpture Garden’s Ring Auditorium, 7th Street and Independence Avenue SW. Free. (202) 633-2795. (Glenn Dixon)