Within the Christian Science Center , one hidden gem deserves special mention. The Mapparium (200 Massachusetts Ave., 617/450-7000, www.marybakereddylibrary.org , 10 a.m.–4 p.m. Tues.–Sun., $6 adults, $4 seniors, students, and youth 6–17, free children under 6) is like nowhere else on the world—maybe because it’s literally inside of it.
Visitors are ushered along a bridge into a 30-foot-diameter globe with the countries of the world (circa 1935) displayed in vibrant stained glass around the walls. For map geeks, it would be possible to spend an hour tracing the outlines of countries and continents, reflecting on their changes over the years.
Every twenty minutes, a seven-minute light show explores the spread of ideas around the globe through the voices of Nelson Mandela, Eleanor Roosevelt, and other seminal thinkers.