Just as the name of this natural attraction implies, a sea cave is formed by the ongoing smashing of waves into rocky coastlines all around the world. The process of erosion has often been going on for millions of years, resulting in fascinating natural miracles.
Some of these caves can reach a length of up to 1 kilometer (0.6 miles). The longest surveyed sea cave is called Matainaka Cave and is located on the Otago Coast in the southeastern part of New Zealand’s South Island. It’s an astounding 1.5 kilometers (0.93 miles) in length and wasn’t formed overnight.
The list below features some of the most famous sea caves in the world. These aren’t all this long but do feature unique qualities that make them both intriguing and beautiful.
1. Blue Grotto – Capri, Italy
The Blue Grotto, locally known as the “Grotta Azzura,” is one of the most fascinating sea caves in the world for multiple reasons. It’s located on the small island of Capri in southern Italy which has been a popular tourist attraction since the ancient Roman Republic days.
What makes this cave so intriguing is that it can only be accessed through a small arched portal. This in combination with a larger opening below it creates a unique blue hue inside the cave. This is one of the reasons why Roman Emperor Tiberius, the second Roman Emperor after Augustus, made it one of his swimming holes.
2. Cenote Dos Ojos – Tulum, Mexico
Cenote Dos Ojos is a system of caves locally known as the “Sistema dos Ojos,” a reference to the two main cenotes or “sinkholes” that have the appearance of two eyes located right next to the caves. This immense cave system has only been surveyed since 1987 and 82 kilometers (51 miles) have been mapped already.
This magnificent labyrinth of magnificent caves and sea caves is located on the Yucatán Peninsula in the Mexican state of Quintana Roo. This is situated in the utmost southeastern part of the country. Apart from their magnificent appearance, the water inside the caves is also crystal clear as the rainwater is filtered through the limestone.
3. Fingal’s Cave – Staffa, Scotland
One of the most astounding sea caves in the world is called Fingal’s Cave and is located on an uninhabited island called Staffa. This island is part of Scotland and can be found on an archipelago known as the Inner Hebrides on the western coast of the country.
What’s remarkable about this particular cave is that it’s formed from basalt columns that were erected during a lava flow in the geological epoch called the Paleocene, approximately between 66 and 56 million years ago. The sea carved these columns into one of the most fascinating natural works of art on the planet.
4. Phang Nga Bay Caves – Phuket, Thailand
Phang Nga Bay is a bay located in the Strait of Malacca which lies in between the island of Phuket and the southern part of mainland Thailand. A large section of this bay consists of a protected area called Ao Phang Nga National Park and is world-famous for its remarkable limestone rock formations.
Apart from these limestone cliffs, the bay is also home to a large number of sea caves that have been carved into the coastline and cliffs. These are easily some of the most magnificent sea caves in the world and have become an extremely popular tourist attraction in Thailand.
5. Neptune’s Grotto – Alghero, Italy
Neptune’s Grotto is a sea cave located in the northwestern part of the Italian island of Sardinia. This stalactite cave was only discovered in the 18th century and has become a popular tourist attraction on the island ever since. The reason for that is fairly simple because it’s one of the most amazing caves in the world.
Entering the cave isn’t as straightforward as it seems as well because its entrance is located just 1 meter (3 feet) above sea level. It can only be reached via a staircase that was cut into the cliff called the “Escala del Cabirol” (goat’s steps). It features 654 steps down and the result at the end is breathtaking.
6. Sea Lion Caves – Oregon, United States
One of the best things to do in Oregon is to visit the largest sea cave in the United States. The cave is located about 18 kilometers (11 miles) north of the coastal city of Florence, and as the name of the cave implies, the Sea Lions Cave is inhabited by a large number of sea lions.
The fact that this particular cave is located at sea level means that the seawater is still carving its way into the rocks along the Oregon coastline. The cave already has a floor area of 0.81 hectares (2 acres) and a maximum height of 38 meters (125 feet), making it an amazing sight to behold.
7. Papanikolis Cave – Pelagos, Greece
Papanikolis Cave is considered to be the second-largest sea cave in Greece and it indeed looks quite impressive. It has a length of about 120 meters (393 feet) and a width of about 60 meters (196 feet) and can only be reached by boat.
This cave has a remarkable history as ell because it was originally used as a hideout for sailors from pirates on the Aegaeon Sea. During the Second World War, the cave was used yet again as a hideout, this time for Greek submarines hiding from Italian ships.
8. Admirals Arch – Kangaroo Island, Australia
Admirals Arch is one of the most amazing attractions on Australia’s Kangaroo Island. It’s part of the “Flinders Chase National Park,” a large protected area that covers an area of 326.61 square kilometers (126.1 square miles) in the Australian state of South Australia.
This magnificent sea cave was formed by thousands of years of erosion and weathering from the sea. Just like the Sea Lions Cave in Oregon, this area is also inhabited by marine animals namely fur-seals. This in combination with the amazing natural wonder provides a remarkable sight from the specially designed viewing platform inside the cave.
9. Playa de las Catedrales – Ribadeo, Spain
Playa de las Catedrales is the popular name given to a beach called Praia de Augas Santas. This beach is filled with rock formations and caves and is located near the town of Ribadeo in the northwest of Spain on the Cantabric Coast.
It’s possible to wake inside these remarkable structures, which resemble the buttresses of a cathedral and which is how they got its name, at low tide. This allows you to get a close-up view of how thousands of years of erosion have created these spectacular natural arches.
10. Apostle Island Sea Caves – Wisconsin, United States
Even though they are referred to as being sea caves, the Apostle Island Sea Caves are located on the Apostle Islands, small islands situated on Lake Superior in Wisconsin. That being said, Lake Superior is so big that it does resemble a sea.
Just like the sea caves formed by the seas or oceans of the world, these caves were formed by the water of Lake Superior carving its way through the sandstone of the Apostle Islands National Lakeshore. The result is a combination of impressive arches, marvelous vaulted chambers, and smooth passageways.