Often referred to as the Arcos Naturais, the iconic Double Arch at Praia da Marinha, the distinctive limestone formation of a spectacular double natural sea arch, consisting of two interconnected arches, and located on the western side of the Praia da Marinha Beach in the Algarve region of Portugal, between the towns of Carvoeiro and Armação de Pêra, is formed by the two formidable powers of the nature, wind and sea erosion over millions of years. Viewed from a specific point on the cliffs above, the two majestic limestone arches, along with other rock formations, look like a heart-shaped formation that emerges from the clear turquoise blue water of the Atlantic Ocean, creating a truly stunning coastal landscape, highlighting the natural beauty of the region, and making it one of the most photographed spots in the Algarve region.

The stunning Arch at Praia da Marinha is also a part of the famous Seven Hanging Valleys Trail, a popular and scenic 6-kilometre one-way or 12 km round-trip coastal hike, known for its imposing views of the ocean, the gigantic limestone cliffs, and the scenic natural beauty along with the Alfanzina lighthouse. The moderately challenging trail, linking Praia da Marinha and Praia de Vale Centeanes, is equipped with snorkelling and kayaking facilities, and features numerous grottos, secluded beaches, and breathtaking viewpoints. The trail also includes the famous Benagil Cave, featuring a natural skylight and a small stretch of sand, which is visible from the cliffs, and can only be entered by boats or kayaks or stand-up paddle boards, especially designed for water sports.

The famous Praia da Marinha beach, widely considered one of the most beautiful beaches in Portugal and Europe, is enchanting for its dramatic coastal scenery, along with the stunning golden cliffs and clear blue water, nestling at the base of towering limestone cliffs, which include the double sea arch to the western side of the beach. The contrast between the blue crystal water of the sea and the golden shades of the rocks creates a photographic effect for the visitors. The rocky walls of Praia da Marinha are home to the sea diversity of the area, which includes anemones, sea urchins, sea stars, shrimps, sea weeds, octopuses, and cuttlefishes, and very popular among scuba divers for observing the natural underwater beauty of the Algarve. The cliff-walk offers jaw-dropping panoramic views, especially at sunset, making it a paradise for photographers. However, as the beach is famous for its iconic double sea arches, it remains crowded at any time of the day. It is therefore advisable to reach it early in the morning and avoid Saturdays and Sundays.

At high tide, the beach area shrinks considerably, and some parts are submerged, while cavities, natural swimming pools and paths among the rocks are revealed at low tide, which is the best time to explore the caves, although many of them can only be reached from the sea. However, kayaks and paddle boards are available for visitors from Praia de Vale Centeane to enter narrow grottoes and hidden coves that boats cannot reach. Among the caves, the Benagil Cave, also called Algar de Benagil, the huge domed cave with a beach inside, is one of the top attractions in Portugal, accessible only by boats, kayaks or paddle boards. The other caves include the Crocodile Cave, featuring rock formations that naturally resemble a crocodile, alongside the Pirate Cave and Daws Cave, offering unforgettable views.