EVEN HARVARD'S students will concede, as they scuttle off to class, that much of what is most exciting and diverting about the university has little to do with what goes on in its classrooms.

Set in Cambridge, Mass., just across the Charles River from Boston, Harvard and the surrounding neighborhood are a marvelous mix of academia, eccentricity and excess.

At the center of the university, both physically and psychologically, is Harvard Yard, an area walled off from Cambridge in which almost all the freshmen live in dormitories dating back to before the Revolutionary War, The Yard is largely lawn, meticulously tended and on nice days likely to be filled with Frisbee-tossing freshmen.

In the center of the Yard is the deceptively small administration building, University Hall, in front of which is the notorious "statue of the three lies." The statue purports to depict Harvard's founder, John Harvard, and gives the date of the college's founding as 1636. But John Harvard did not found Harvard, he simply contributed his extensive library to it; the college was founded in 1939, and the man depicted by the statue is not John, who refused to pose for it, but his brother.

Beyond University Hall squats Harvard's vast Widener Library, one of the more impressive things the university was able to build with money from the wills of those who drowned when the Titanic sank. The library, which contains 3 million volumes, about a third of the university's collection, is well worth a visit. The non-stack areas are open to the public, and the building's soaring interior shelters not only one of the most impressive research libraries but also enough eccentric characters to pleasantly pass a half-hour of people-watching.

Widener squares off in the Yard across from Memorial Church, which commemorates the students who died in the first and second world wars. Next to Memorial Church is Sever Hall, currently being renovated. Sever is one of the nation's important architectural monuments. Designed in the late 1800s by H. H. Richardson, it was the first university building designed solely as classroom space.

Beyond the Yard, the university mingles with the city, creating a peculiar response to the peculiar demands of 400 years of academics. The Square, as the area around Harvard is called, is filled with cafes, shops, restaurants and bars. There are probably more bookstores within a four-block radius of the Yard than within any comparable area in the world (a recent estimate put the number at 26).

The Harvard Coop, which stocks textbooks for all the courses, also has an impressive book selection. But much more impressive, and unmatched elsewhere in the Square, are its record and poster divisions. The record department stocks almost everything ever etched in vinyl at prices lower than almost anywhere else in the nation. And the poster department, the size of a small art store, modestly proclaims itself "the largest collection of posters in New England."

In the evening, Cambridge comes alive in the bars and cafes where students and their mentors hang out. There are few better places to meet mad DNA researchers or fanatic scholars of extinct languages. Cafe Pamplona, where the tables are tiny, the waiters notoriously brusque, and the coffee and pastries divine, is among the Square's best cafes. Because it is tucked away in a basement off the main streets, it is frequented more by natives than by tourists. The Algiers, a steamy, crowded cafe on Brattle Street, is modeled after Middle Eastern cafes. The ethnic dishes and the pecan pie are equally good. And there is no place that serves more coffee of dubious quality or more muffins of rubbery texture than Mug 'N' Muffin, a coffee house in the heart of the Square. For $1.16, one can drink all the coffee one desires, gnaw on a microwaved blueberry muffin, read The New York Times, and be in the company of both famed constitutional scholar Archibald Cox and Cambridge's bag people.

Of Harvard's seven museums, the University Museum, the Busch-Reisinger, and the Fogg merit a visit. All are relatively small and relatively fine. The University Museum features the famous collection of glass flowers; the Busch-Reisinger is devoted to German art, including an impressive collection of 20th century works; and the Fogg is one of the nation's outstanding small art museums. It has a permanent collection and is one of the regular stopping places for major national traveling exhibitions as well.

The university's building are impressive not only for what they contain but also for how they look. Although the insides of many are off-limits to the public, many simply provide good viewing from the outside. The Science Center, just north of the Yard, is designed to look like a Polaroid Land camera from the air because its principal donor was the man who developed that camera. Next to the Fogg Art Museum is the Carpenter Center for the Visual Arts, designed by LeCorbusier (who, upon seeing the complete building for the first time, is alleged to have joked, "Ah, but they have built it upside down!"). And next to the Science Center is the building now used for classical music concerts and final exams, Memorial Hall. Drafty, noisy and imposing, the cathedral-like structure was originally a combination lecture hall and dining hall.

(For more information, the best place to inquire is Harvard's Information Office, in Holyoke Center next to Mug 'N' Muffin.)