Sea caves are incredible, forming along cliffs through erosion with only the power of wind and water. There are many stunning sea caves around the world that are well-known with hundreds of thousands of tourists visiting each year, such as New Zealand’s Matainaka Cave (the largest sea cave in the world). However, there are many more sea caves that are less known, tucked away along coastlines that aren’t as popular or easily accessed. From the beaches of Portugal to the island of Scotland, why not plan a trip to one of the most spectacular sea caves around the globe.
Waiahuakua Cave, Kauai, Hawaii, USA
It ranks as one of the world’s longest sea caves in the world at 1,155 feet. It is often referred to as the “double door cave” as it has both an entrance and an exit. The cave is located along Kauai’s Na Pali and is only accessible by water. Visitors sometimes refer to it as dark and spooky but fear not when you head into the cave as you’ll be treated with some incredible sights. Unusual features include a large cathedral room, a white-lit tunnel hallway, and a pinkish-red rock shaped like a hippo. The most magical part of this cave though is the waterfall that streams through a fissure in the ceiling. At certain times of the day when the light catches it the right way, the waterfall looks more like a bolt of lightning.
Benagil Beach Sea Cave, Algarve, Portugal
This beautiful dome of a sea cave is located in the tiny town of Benagil and is one of the best gems of the whole Algarve coast. To get there you either have to take a local boat or rent a kayak and paddle out, though some visitors have swum out, as it’s located just to the east of the village on the beach.
The cave is simply stunning, with a skylight at the top letting the light shine in, illuminating the sand below and warm waters which you can swim in. Whether you visit during high or low tide, you can expect the same amazing experience. If you take a tour with a guide, be sure to choose one that lets you spend some time exploring, as many buzz in and out of the caves in a hurry.
Smoo Cave, Durness, Scotland
This impressive geological wonder includes both fresh water and seawater and was actually carved into the limestone by the Alt Smoo, a river that runs above and pours into a cavern through a sinkhole. Nearly 40,000 people visit each year and recent improvements include new walkways, washrooms, and other amenities for visitors. The main entrance to the cave is quite interesting in that it has one the largest entrances in Britain at 50 feet high that was formed by the sea while the inner chambers were created by the river.
Going there to view the entrance and main cave is free but for a small amount, visitors can take a tour into the smaller chambers and see a beautiful waterfall. The tour is definitely recommended, but be sure you go early as they fill up fast. One of the most unique sea caves on this list, it’s not to be missed if you happen to be in Scotland.
Sea Lion Cave, Florence, Oregon, USA
It wouldn’t be a complete list of sea caves without including America’s largest sea cave, the Sea Lion Cave, which gets its name from the resident sea lions that lounge around, barking excessively. The formation of this cave happened about 25 million years ago and now is as large as the length of a football field and as high as a 12-story building. Although it has become quite a popular tourist attraction – there’s even an elevator that takes you down to the cave – it’s simply a wonder that must not be missed.
Besides sea lions, visitors will have the chance to take in the colors of the cave as over years lichen, minerals, and algae have painted it in hues of pinks, purples, and reds. Other animals you may see in and around the cave are sea birds and whales. Visitors must be able to walk along the trails and steps down to the cave and should be prepared that there are not always sea lions present (to avoid disappointment), as this is the wild, not the zoo.
Fingal’s Cave, Staffa, Scotland
This sea cave is located on the island of Staffa and is known as the cave of melody or as novelist Sir Walter Scott explained, “one of the most extraordinary places I have ever beheld”. Fingal’s Cave is well-known for two things: the eerie sounds it makes and the arching cathedral-like geological features. In fact, the entire cave is made up of hexagonal basalt columns and is the only one of its kind in the entire world. Visitors can discover this cave by taking a sightseeing cruise from the town of Hull. The cruise ship will land close to the cave and the basalt columns actually provide the perfect stepping stones to enter the cave. When it groans and moans, just know that these sounds are quite normal for this sea cave.
Blue Grotto, Capri, Italy
The Blue Grotto is one of the most well-known sea caves around the world, and for good reason. Back in Roman times, it was the personal swimming hole for Emperor Tiberius and in the 1960s there were three Roman statues of sea gods found on the ocean floor. For years this cave was avoided as locals believed it was inhabited by evil spirits and monsters. Today though, it is enjoyed by many, though swimming is not allowed.
To enter the cave, visitors must take a boat and lay flat down on the bottom in order to get through the small 4×4 entrance. What makes this cave so special is the color of the water inside, as it glows a bright and brilliant blue, a color so unworldly it’s hard to believe it exists. Visitors wanting to go inside this cave should be aware that inclement weather may lead to an unsafe passage and therefore trips may be delayed or canceled on short notice.
Painted Cave, California, USA
Located on the craggy coast of Santa Cruz Island in California, this is one of the largest and deepest sea caves in the world. At over 130 feet high and nearly a quarter-mile long, this sea cave gets its name from the numerous colors that make it up. Colorful rocks, lichen, and algae adorn the walls of the cave, turning it into a colorful piece of art. The cave is made up of several inner chambers and the best way to explore them is by taking a boat to the island and then kayaking your way through the cave. Visiting in the springtime is perhaps the best time, as a beautiful waterfall cascades down in front of the entrance to the cave. There are many guided tours to choose from which will provide you with all the gear, flotation devices, snorkels, and information you need.
Apostle Island Sea Caves, Wisconsin, USA
The Apostle Islands are home to some of the most spectacular caves on the planet, and although they aren’t located in the “sea” (instead they are in Lake Superior) they are still technically referred to as sea caves. Summertime brings boaters and kayakers to the lake to explore the caves that feature red sandstone cliffs, the sparkling lake, and forested trees in the distance, with forceful waves spraying and breaking into the caves. It is extremely important to check weather and water conditions before you head into the caves as it can be quite dangerous.
Wintertime is when these caves really shine through. As Lake Superior freezes in the winter, so do the damp caves and waterfalls, creating incredible ice formations both in and outside the caves. When the lake is sufficiently frozen over, visitors can hike, snowshoe or ski to gain access to this winter wonderland.
Cathedral Cove Sea Cave, Coromandel, New Zealand
Cathedral Cove holds a total of five incredible sea caves along the Catlins Coast of southeastern New Zealand. There are actually two main cave systems that join together with the cliff, one having a ceiling height of 100 feet. Getting to the caves at the right moment is the hard part is they are only accessible for two hours on either side of low tide. The reward is worth it though – getting to explore an area that is otherwise always underwater, a place where visitors can often spot blue penguins and fur seals from the gloomy end of the cave. If you’re planning on visiting be sure to check the tides and bring a headlamp or flashlight, as the caves are extremely dark.
Cuevas de Mármol, Chile Chico, Chile
It seems that Mother Nature has outdone herself with this last set of stunning sea caves. Carved into the Patagonian Andes, the Cuevas de Mármol are located on a peninsula of solid marble bordering Lake General Carrera, a remote glacial lake that spans the Chile-Argentina border. This block of marble is said to weigh over five billion tonnes. The caves have been formed over thousands of years of waves washing up against the calcium carbonate. The colors of both the lake and caves change depending on the time of year and water level and the luckiest visitors can experience swirling blue cavern walls and azure waters. To get here, visitors must take a boat a thirty-minute tour, operated by a local guide company (weather and water conditions permitting, of course).
