Children's museums become an essential part of our play menu. Here are 4 famous muse-ums for families.

KidsQuest Children's Museum

It features huge windows, beautifully designed exhibits and an adventurous, two-story rope ladders in the opening gallery. Kids of all ages will love building with real tools in the re-cycled room, running the cash register, doing physics experiments on water in the Water Lab and much more. Reservations are required. You can make them online.

Imagine Children's Museum

Imagine Children's Museum's new 33,000-square-foot expansion doubles the museum's previous play space and its shows. At over 60,000 square feet, its current area is much bigger than other local children's museums (which average around 10,000-20,000 square feet). Visitors can spend hours in the museum.

Children's Museum of Tacoma

At 10,000 square feet in size, the Children's Museum of Tacoma has a huge draw. Since it opened about a decade ago, it has offered pay-as-you-will admission and has no plans to change that anytime soon. This means that you can stop off for an hour, without worrying about whether you've gotten your money's worth.

Seattle Children's Museum

This kid-favorite spot is located on the lower level of the Seattle Center Armory building. Long-time museum lovers will notice a new exhibit, a post office where kids can weigh packages and slide behind the driver's seat to make pretend deliveries.