Covão dos Conchos: Portugal’s Enigmatic Sinkhole Reservoir

covao dos conchos

Hidden deep within the Serra da Estrela mountain range, the largest in Portugal, lies a geological marvel that has fascinated visitors and locals alike for generations. Covão dos Conchos, often referred to as Portugal’s “eye,” is a sinkhole reservoir that seems to defy the laws of nature. Its captivating allure, surrounded by the pristine beauty of the Serra da Estrela, invites adventurers to explore a natural wonder that has mystified the curious and inquisitive.

The Enigmatic Sinkhole Reservoir

Covão dos Conchos is a man-made reservoir constructed in the early 1950s as part of a hydroelectric project. The dammed Zêzere River collects water, which is then conveyed through a tunnel beneath the mountain. What makes Covão dos Conchos particularly enchanting is the surreal, circular hole or “eye” in the middle of the reservoir.

covao dos conchos3

The Eye of the Reservoir

The “eye” is a hole measuring approximately 4.6 meters in diameter, resembling an otherworldly portal to an underground realm. In reality, this aperture serves a functional purpose: it is a spillway that allows excess water to flow beneath the surface and into the tunnel system. However, the stark contrast between the serene, mirror-like surface of the reservoir and the turbulent, churning water that disappears into the “eye” creates a mesmerizing visual effect that has drawn the attention of photographers, explorers, and nature enthusiasts.

Accessing Covão dos Conchos

To reach this remote wonder, adventurers embark on a trek through the rugged terrain of the Serra da Estrela. The journey to Covão dos Conchos typically starts at the village of Manteigas and takes several hours, involving steep ascents and descents. The terrain can be challenging, so it’s advisable to be well-prepared and equipped for the hike. The trail leads to an overlook where visitors can marvel at the breathtaking sight of the sinkhole reservoir and its enigmatic “eye.”

covao dos conchos1

Seasonal Changes

The appearance of Covão dos Conchos can change dramatically throughout the year. In the spring and early summer, the reservoir fills to capacity, presenting a strikingly tranquil surface. However, during the fall and winter, the reservoir can be nearly empty, revealing the intricate and rocky landscape beneath.

Preservation and Conservation

Covão dos Conchos is part of the Natura 2000 network, a European initiative that aims to protect and conserve the continent’s most valuable and threatened habitats and species. Preservation efforts focus on maintaining the ecological balance of the area while allowing visitors to enjoy the mesmerizing beauty of this geological wonder.

covao dos conchos2


Covão dos Conchos stands as a testament to the intricate workings of nature and human engineering. Its allure is not only in the mysterious “eye” that captivates all who see it but also in the pristine surroundings of the Serra da Estrela, Portugal’s highest mountains. This enigmatic sinkhole reservoir invites those who venture here to explore the hidden beauty of the natural world, where science and artistry converge to create a sight that lingers in the memory long after the journey is complete.

Found something amazing? Spread the wonder and share it with your friends! 🥰