Olympic National Park

At more than 922,000 acres — and 95 percent of that area classified as wilderness — there are few places on Earth with as much geographic diversity as Olympic National Park in Washington. Mountains in its interior, a rugged Pacific coastline and a rain forest grace the park. The Hoh Rainforest is the largest temperate rain forest in the world, where the temperature rarely drops below freezing or goes above 80 degrees Fahrenheit.

Andy and Lisa Greider of Stone Mountain, Ga., have visited the park with daughter Ari, 16, and son Rowan, 8, several times; they always marvel at the sheer variety of climate and geography within a compact area. "You can trek from the tidal pools to the rain forest to the tundra in less than a day," says Andy, "but I always recommend at least four days."