There are a total of five islands that make up the archepelago known as the Hawaiian Islands (Kauai, Oahu, Molokai, Lanai, Maui, and Hawaii). Sometimes labeled "The Grand Canyon of the Pacific", Waimea Canyon located on the island of Kauai is 14 miles long and 3600 feet deep.
Located on 180 acres of protected royal grounds in Kona, Puuhonua o Honaunau National Historical Park is one of Hawaii's most sacred places spanning hundreds of years... Kapu, which stands for a code of conduct of laws and breaking them can result in death UNLESS you made it to the sacred grounds. Once there, a ceremony would ensue and the law breaker would receive absolution and be released back into society.
The Kalaupapa Peninsula, which is located on Molokai's North Shore Pali has the tallest sea cliffs in the world as per The Guinness Book of World Records! The cliffs in Kalaupapa National Historic Park measure between 3600 and 3900 feet. The shores located below the Cliffs of Moher, which seem far from the top, are only 702 feet down, which is between 2898 and 3198 feet shorter than the cliff located in Kalaupapa!
There are many more national parks located through the popular archepelago, but these three are the most popular.