Juromenha Fortress, in the municipality of Alandroal, is a monument of great historical value that has gone through several transformations over the centuries. Dating back to the Roman occupation, it played a crucial military role during the Islamic period and was conquered by the first Portuguese king in the 12th century. Its architecture has undergone work numerous times, particularly after the devastating earthquake of 1755. Today, the fortress stands majestically on the right bank of the Guadiana River, on the natural border between Portugal and Spain, in a strategic position that allows visitors to admire the landscape around it in every direction.

As the fortress stands in the Dark Sky Alqueva Reserve, a protected area committed to preserving the natural night sky, lighting it presented a fascinating challenge. The project was carried out in collaboration with a team from the Lisbon School of Architecture, and it aimed to enhance the restoration and ensure the monument could be seen from a distance without compromising the integrity of the surrounding environment or the visibility of the starry night skies. 

From the outset, the design team planned to use warm lighting (2700K for the exterior walls and 3000K for the interior and the church), chosen to respect the limits for light pollution while still guaranteeing visitor safety. Light intensity was reduced to a minimum. The light output was precisely distributed by Ginko 2.0 fixtures, which were used with various optics, including elliptical ones. Horizontal elliptical optics were used along the exterior walls to ensure maximum uniformity, while vertical light beams were used for the towers and prominent corners. To further optimise light management, honeycomb louvres were built into the fixtures to reduce glare. These solutions have ensured uniform, efficient lighting that minimises light spills.

The lighting tests conducted on Portugal’s National Castle Day confirmed the choice of technological solutions, which strictly comply with the Dark Sky Reserve standards. The use of finishes such as corten for the poles and the fixtures, together with the careful management of luminous fluxes, has guaranteed a perfect balance between enhancing the historical heritage and respecting the natural environment.

This project perfectly demonstrates how responsible, carefully designed lighting can protect historical heritage and respect the environment while at the same time offering a unique experience to visitors to the Juromenha Fortress, bringing out its beauty without compromising the natural night sky.

“Light2Life has worked with the Dark Sky Reserve team for many years. For the Fortaleza de Juromenha, the goal was to illuminate the building so that it would stand out for locals, the surrounding cities and visitors, while respecting the extremely sensitive environment of the Dark Sky Alqueva Reserve. The colour temperature was set at 2700K from the outset, and lux levels were adjusted after numerous detailed light tests. The final solution involved the use of 4-metre-long square corten light poles, with several Ginko 2.0 fixtures installed on all four sides. To ensure the greatest possible uniformity along all the outer walls, we used horizontal elliptical optics, while vertical optics were used to highlight the main corners and towers.” Pedro Telhado, lighting designer at Light2Life