Boston's Left Bank—an uberliberal academic enclave—is a must-visit if you're spending more than a day or two in the Boston area. It's packed with world-class cultural institutions, quirky shops, and restaurants galore.
The city is punctuated at one end by the funky architecture of MIT and at the other by the grand academic fortress that is Harvard University. Civic life connects the two camps into an urban stew of 100,000 residents who represent nearly every nationality in the world, work at every kind of job from tenured professor to taxi driver, and are passionate about living on this side of the river.
The Charles River is the Cantabrigians' backyard, and there's virtually no place in Cambridge more than a 10-minute walk from its banks. Strolling, running, or biking is one of the great pleasures of Cambridge, and your views will include graceful bridges, the distant Boston skyline, crew teams rowing through the calm water, and the elegant spires of Harvard soaring into the sky.
No visit to Cambridge is complete without an afternoon (at least) in Harvard Square. It's a hub, a hot spot, and home to every variation of the human condition: Nobel laureates, homeless buskers, trust-fund babies, and working-class Joes. Farther along Massachusetts Avenue is Central Square, an ethnic melting pot of people and restaurants. Ten minutes more bring you to MIT, with its eclectic architecture from postwar pedestrian to Frank Gehry's futuristic fantasyland. In addition to providing a stellar view, the Massachusetts Avenue Bridge, spanning the Charles from Cambridge to Boston, is also notorious in MIT lore for its Smoot measurements.