Founded only 16 years after the Pilgrims landed at Plymouth, Harvard University counts six U.S. presidents and numerous Nobel laureates as alumni. Standing in Harvard Yard, in front of the imposing Widener Library (third largest in the U.S., largest university library in the world), you can feel the history. And yes, many of the halls, representing four centuries of architecture, are covered in ivy. June and August student-led tours depart Monday-Saturday at 10 and 11:15 am, 2 and 3:15 pm. During the academic year, tours depart Monday-Friday at 10 am and 2 pm, Saturday at 2 pm. Free. Tours start at the Holyoke Center, 1350 Massachusetts Ave., Cambridge. Phone 617-495-1573. http://www.news.harvard.edu/guide/to_do/index.html.
