Sequoia and Kings Canyon National Parks
To kids, bigger is always better. That's why they'll be awed when they stand next to the largest trees on earth at this park in the Sierra Nevada mountain range. Many of the sequoias are as tall as a 26-story building and as wide as a city street. These big trees also spawn long pinecones and gargantuan roots -- providing hours of enjoyment for young ones. Don't spend all of your time at the celebrity trees -- General Sherman and General Grant -- or you'll miss out on kid-friendly trails, which lead to breathtaking mountaintop views and glacial lakes.
Setting Up Camp
Here, you have three lodge areas and 14 campgrounds, but the kids will definitely want to sleep outside under the giant trees. Lodgepole campground ($16 per night; 800-365-2267) has laundry and shower facilities, a post office, and horseback riding. If you're not a camper, check out the new Wuksachi Village and Lodge, which has terrific mountaintop views. (Rates start at $75 per night; 888-252-5757).
Crystal Cave, near Giant Forest, is a marble cavern filled with stalactites and stalagmites. The 60-minute underground tour keeps antsy preschoolers occupied. (You must make advance reservations at the Foothills or Lodgepole visitors' centers; adults, $6; children ages 6 to 12, $3).
This area is home to wild animals such as mountain lions. Stay close together on trails.