5 Top Sea Caves and Grottos in Portugal

Written By Lara Silva

Portugal is known for the beauty of its coastline, and some of the most captivating natural wonders are its sea caves and grottos. These geological formations, shaped by the power of the sea are a sight to be seen.

If you’re planning a trip to Portugal, make sure to include a visit to at least one of these 5 top sea caves and grottos. From the Algar de Benagil to the Gruta do Capitão, each sea cave and grotto has its own unique character and geology.

Whether you’re a nature enthusiast or a beach lover, these geological wonders are worth a visit. Let’s take a look at the 5 top sea caves and grottos in Portugal!

1. Algar de Benagil, Portimão

By far, the most famous sea cave in Portugal is the Algar de Benagil in Portimão, Algarve. If you have seen a photo of a blue-watered sea cave in Portugal, this is likely to be the one. This cave is widely considered one of the most stunning natural wonders in the region.

The cave is famous for its large dome-shaped opening that allows sunlight to filter in, creating a beautiful natural light show inside the cave. The interior is filled with intricate rock formations, sparkling waters, and a small beach that can be reached by boat or swim.

Time for some geology? The Algar de Benagil was formed over thousands of years through the erosion of the surrounding cliffs by the sea. The collapse of the cave ceiling has resulted in the current dome-shaped opening, which is approximately 20 meters in diameter.

You can paddle or kayak to the sea caves from Benagil Beach if the ocean conditions allow, although the current can make it difficult. However, the safest and best way to get to Algar de Benagil is to book a boat tour.

We recommend booking this 2-hour tour from Portimão, which includes a visit to the Benagil Cave. You can also expect to see spectacular rock formations, crystal-clear waters, and hidden beaches that are only accessible by boat. The tour is led by an experienced guide who provides insights into the marine life and ecology of the area. 

Benagil Caves. Photo by 777 S (Unsplash)

2. Algar do Carvão, Terceira

Algar do Carvão is a famous volcanic chimney located on the island of Terceira in the Azores archipelago. It is one of the most impressive geological formations in the region and is a must-visit for anyone interested in earth sciences or natural history.

The chimney was formed approximately 3000 years ago during a volcanic eruption, and it is estimated to be around 90 meters deep. The walls of the chimney are adorned with intricate mineral deposits and formations, including stalactites and stalagmites. 

If you are lucky enough to visit Algar do Carvão, you can explore the inside of the chimney by descending a staircase that has been installed for that purpose. Along the way, you will find the various rock formations that make up the walls of the chimney. There is also a small lake at the bottom of the chimney, which is fed by a natural spring.

There are many tours that take you to this algar, as well as other nearby attractions. We recommend this popular excursion that takes visitors on a journey through the island’s volcanic caves and grottos, including the Algar do Carvão. It is a unique and educational experience that showcases the geological history of the Azores. You will be able to descend into the crater of the Algar do Carvão and observe the various rock formations and geologic layers that have accumulated over the years.

The tour also includes a visit to the Furnas do Enxofre, a sulfur cave that emits a distinct smell due to its mineral content. You will learn about the unique ecosystem, including small creatures and plants that have adapted to the unique conditions.

Algar do Carvão, Terceira. Photo by Vitor Oliveira (Flickr)

3. Zorreira Cave, Portimão

Zorreira Cave is a unique geological formation located in Portimão, formed over thousands of years. It is known in the area for its intricate stalactites, stalagmites, and other mineral formations. The cave is approximately 40 meters deep and can only be accessed by boat.

The geology of Zorreira Cave is fascinating, with the mineral formations taking on a range of shapes and sizes. The stalactites and stalagmites have been formed over millions of years by the slow drip of mineral-rich water. The colors and shapes of the formations vary greatly, adding to the cave’s unique beauty.

Visitors to Zorreira Cave are advised to wear appropriate footwear, as the cave can be slippery in places. It is also recommended that visitors bring a jacket, as the temperature inside the cave can be cooler than the outside temperature. Guided tours typically last around two hours and include a visit to other nearby caves and grottos, making it a comprehensive exploration of the region’s natural wonders.

In summary, Zorreira Cave is a famous geological formation that is a must-visit destination for anyone traveling to Portimao, Portugal. The cave’s intricate mineral formations and unique beauty make it a stunning natural wonder that should not be missed. Visitors can access the cave by joining guided tours that depart from Portimao and can expect to spend around two hours exploring the cave and other nearby geological formations.

4. Gruta do Capitão, Armação de Pêra

Also known as the Captain’s Cave, Gruta do Capitão is a popular natural attraction located near Armação de Pera in the Algarve. The cave is named after the captain who discovered it in the 20th century. To visit Gruta do Capitão, it is recommended to book a guided tour in advance. 

The geology of the cave is fascinating, as it was formed from limestone rock that was eroded by water over time. As the water slowly drips through the rock, it deposits minerals that build up over time and create the formations we see today.

This has resulted in the cave’s interior being decorated with stalagmites and stalactites, columns, and curtains of calcite, formed over thousands of years by this dripping water.

The colors and textures of the rocks create a unique sight, one you will want to photograph. This cave has also been known to humans for centuries as artifacts from the Paleolithic era have been found within the cave, indicating that it was used by early humans for shelter and possibly even for ritual purposes. 

5. Cabo Espichel, Arrabida

Cabo Espichel is a rugged cliff formation located at the western end of the Serra da Arrabida mountain range in Portugal. It is a popular destination for tourists who come to see its stunning views of the Atlantic Ocean and its unique geological features.

The cliffs are made up of layers of limestone and sandstone, which have been eroded over time by wind and water to create a dramatic landscape. Within these cliffs, hidden sea caves have been formed throughout the years.

This tour of the Secret Beaches of Arrabida takes you on a journey to discover some of the most secluded beaches and sea caves in the region. You will explore the Arrabida Natural Park, and visit some hidden beaches that are not easily accessible by car. The tour stops at Cabo Espichel, where you will be able to see beautiful cliffs and, finally – stunning hidden sea caves!

Cabo Espichel, Arrabida. Photo by Paulo Valdivieso (Flickr)
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