Honokohau Falls, Maui. This is breathtaking—It plunges in two tiers for a total of 1600 feet, making it the second highest falls in the United States (only Yosemite Falls is higher). And, it's where they filmed Jurassic Park!
Iao Valley State Park in Maui is a beautiful, lush place for a hike, but the land also holds some interesting history. It was in this spot in 1790 that King Kamehameha defeated Maui's army and changed the fate of Hawaii. The win allowed him to move forward with his mission of uniting the Hawaiian islands.