Sierra Sur de Jaén Starlight Reserve

With a background of mountains and ravines, in the Sierra Sur Starlight Reserve the stars shine like beacons in the dark, because the clear, transparent air makes star gazing a unique experience. 

The Sierra Sur de Jaén Starlight Reserve has an extraordinary natural heritage and its greatest treasure is the magnificent night sky. A team of experts has decided which are the best observation areas, places which are out of the reach of light pollution and where the sky still retains its natural darkness that has disappeared in so many places. The Sierra Sur de Jaén enjoys an incredibly starry sky and clear nights and magnificent installations await you.

Ten municipalities in the Sierra Sur de Jaén have tourist attractions linked to stargazing and it has been a certified Starlight Destination since August 2014. This distinction is in addition to that already awarded in March 2014 as a Starlight Reserve and endorses the quality of the night sky in this region and its suitability for astronomy and stargazing in the best conditions.

This has led to the declaration of the municipalities of Alcalá la Real, Alcaudete, Castillo de Locubín, Frailes, Fuensanta de Martos, Martos, Valdepeñas de Jaén, Jamilena, Torredelcampo and Los Villares, all in the province of Jaén, to be included in one of the most select and exclusive groups of Starlight Destinations in the world with the acknowledgement detailed above.

The passion for this exciting science nothing new in the Sierra Sur region of Jaén, which has two long-established amateur associations providing a calendar of informative activities throughout the year:

• The Martos Hubble Astronomical Association organises numerous public observations, courses and all kinds of activities. One of the highlights of the year is the AstroMartos astronomical event which has a significant regional impact.
• The Einstein Astronomical Society, in Alcalá la Real, together with the Andalusian Astronomical Observatory in the nearby district of La Pedriza, organises guided tours and observations for groups and educational centres.

Both are firmly committed to star tourism, research and the conservation of the night sky in the region as a whole. Few places can boast of such conditions for the practice of astronomy, with magnificent installations managed and guided by professional scientists and educationalists.

Description of the Sierra Sur region of Jaén and the quality of the night sky

The region of the Sierra Sur de Jaen provides a very heterogeneous territorial panorama, which includes areas ranging from very abrupt reliefs consisting of narrow ravines, box canyons and steep rock walls, to peaceful olive groves that are a common feature all over the province. In general terms, the geographical area can be divided into two large regions for this specific purpose: 

• The eastern area of the region consisting of the Sierra Sur massif (where you may find differences in altitude of more than 1,870 metres, such as Mount Pandera) and which includes the largest tectonic window on the European continent.
• The peripheral belt of the mountainous area that extends from the north to the south of the region on the western flank. 

The above-mentioned territorial division responds to the fact that both areas have very different lighting conditions and although in the mountainous nucleus the figures for the background brightness of the sky exceed 21.52 mag/arg sec², in the peripheral area where most of the population lives the figures range between 21 and 21.3 mag/arg sec².