The Hawaiian Islands are absolute paradise for lovers of the outdoors, full of majestic mountain peaks, pristine beaches with turquoise water, breathtaking waterfalls and awe-inspiring volcanoes. And while everyone knows about Hawaii’s most famous natural wonders – like Waimea Canyon, Mount Haleakala, Akaka Falls, and Diamond Head, there are a few lesser-known wonders hiding across Hawaii.

1. Oahu’s Mermaid Cave

While many people have heard of the Mermaid Cave, not many have actually been there, or even know where it is. Rumor has it that this luminous cave is located on Oahu’s leeward coast, and if you’re able to find it, or have someone take you there, you are sure to create a memory that will last a lifetime.

2. Golden Ponds of Keawaiki

In the middle of a massive lava field, on the Big Island’s Kohala Coast, is this pair of freshwater pools, home to a thriving population of golden algae that gives the pools a luminescent glow.

3. Mo’omomi Preserve

This sprawling 921-acre preserve on Molokai protects one of the state’s last intact coastal regions, boasting sand dunes a mile long and hundreds of feet wide. Home to native plant species, Mo’omomi is also a nesting site for native shorebirds, the Hawaiian owl, and green sea turtles.

4. Mokolea Lava Pools

Located on Kauai, this partially-submerged lava formation sits approximately 20-feet above sea level. Incoming tidal waves exceed this height, and create a series of dramatic tide pools.

5. Kauai’s Lithified Sand Dunes

Along Kauai's southern shore are sand dunes that have turned to stone over time, and are now being eroded by ocean waves. To reach the lithified sand dunes, take the trail that begins at Kawailoa Bay.

6. Makauwahi Cave

This relatively unknown archaeological site is home to Kauai’s largest limestone cave that was formed when the once fossilized sand dune collapsed. After you squeeze through the mouth of the cave, you will be rewarded with stunning views of a spacious open-air amphitheater.

7. Wainiha Valley Preserve

With more than 7,000 acres of untouched beauty, the Wainiha Preserve is one of the largest nature sanctuaries in Hawaii. Home to more than 200 plant species unique to Hawaii, the preserve is Kauai's primary source of water.

8. Molokai’s Sea Cliffs

Towering at more than 3,500 feet on Molokai's north shore are these impressive sea cliffs inaccessible via land. Viewable via boat or helicopter tour, these are among the tallest sea cliffs in the world.

9. Spitting Caves

Located on Oahu’s southeastern shore are these picturesque Spitting Caves, found below a high cliff where waves crash underneath and shoot into the cave, ejecting the water like a reverse blowhole.

10. Kaumana Lava Tubes

Hawaii Volcanoes National Park’s Thurston Lava Tube gets all the credit, but Kaumana Cave, located near Hilo, is certainly worth the visit. The skylight entrance drops into two miles of pitch-black cave, complete with stalactites and stalagmites, as well as vines and roots falling from the cave’s roof.

11. Maui’s Heart Rock

Naturally eroded by pounding surf, this beautiful little treasure can be found near the Nakalele Blowhole.

12. Pe’epe’e Falls

Located just one mile past the famous Rainbow Falls on Wailuku River is Pe’epe’e Falls. Connected by a series of cascading waterfalls along columns that were formed from the slow cooling of basalt lava, these pools appear to be bubbling – almost as if they were boiling.

13. Waikamoi Preserve

Home to one of the the most diverse forest ecosystems in Hawaii, the Waikamoi Preserve is more than 5,000 acres of pure, untouched natural beauty.

How many of these little known natural wonders have you visited? Which is your favorite?