2 Best Sights in The Monadnocks and Merrimack Valley, New Hampshire

New England's only air-and-space center offers a full day of activities focused mostly on the heavens. See yourself in infrared light, learn about lunar spacecraft, examine a replica of the Mercury-Redstone rocket, or experience what it's like to travel in space—you can even try your hand at being a television weather announcer. There's also a café.

The world's largest permanent LEGO installation at minifigure scale, depicting Amoskeag Millyard and Manchester as they looked a century ago, is the star attraction at this hands-on science lab and children's museum. The mind-blowing exhibit, covering 2,000 square feet, is made up of about 3 million LEGO bricks. It conveys the massive size and importance of the mills, which ran a mile on each side of the Merrimack. The museum also contains touch-friendly interactive exhibits and offers daily science demonstrations.