This waterfront construction project—technically called the "depression of the Central Artery"—aims to move more than seven miles of highway underground and replace the existing surface roads with a network of parks, all by 2004. The Big Dig is a nightmare for anyone with adult concerns such as getting from one place to another, but for kids it's a cool sideshow. They're thrilled by the giant cranes, dump trucks, and unfinished overpasses that end in midair. There's an exhibition on the project at the Museum of Science, where a make-believe elevator ride leads to the "harbor tunnel" and a 3-D video of subterranean work sites.
On summer Sundays a tree-lined stretch of Memorial Drive , running along the Charles River between Harvard and Central Squares in Cambridge, is closed to traffic. Ned and Ella join the crowds to ride their bikes and skateboards here; they often rent in-line skates from vans parked along the river.
There's no need to choose "One if by land, two if by sea" on the Boston Duck Tours . Jack loves to do both—that is, take a ride in a World War II-era amphibious landing vehicle that drives straight into the Charles River. (Departs from the Prudential Center, Boylston St.; 617/723-3825; April-November.)
It's a little hokey to heave a make-believe bale of tea off the Boston Tea Party Ship (Congress St. Bridge; 617/338-1773; open March-November), only to hoist it back up by a chain. But it's a lot of fun, and the lesson on the 1773 tea-tax protest is one even children can understand. The museum store has a fabulous selection of children's toys, books, and games related to the history of Boston.
Meghan adores the Swan Boats (617/522-1966) as much as her parents, and their parents—and even their parents—did. Since 1877 the boats have been pedaled around the Public Garden's lagoon, under beautiful weeping willows and around small islands inhabited by ducks.
Susannah gets bleacher seats to watch the Red Sox play at Fenway Park . When the Sox aren't playing, kids can tour the dugout, locker rooms, and VIP suites, and run on the warning track at the playing field. (4 Yawkey Way; tours 617/236-6666; season runs April-September.)