Alcornocal de Boxo

Alcornocal de Boxo is a small but remarkable natural monument in western Asturias, within the municipality of Allande. This patch of cork oak forest is considered the most important and best-preserved stand of the species in all of Asturias, making it a genuine rarity on a regional scale.

Why is a cork oak forest so unusual here?

Cork oak (Quercus suber) is typically associated with the Mediterranean climate — warmer and drier than humid, Atlantic Asturias. Yet in the Navia river basin, the species found conditions that, paradoxically, allow it to thrive: high humidity, rainfall exceeding 1,000 mm a year, and moderate temperatures. This unusual combination is why a forest that shouldn't exist here by the usual rules of biogeography has survived on the southern slope of the Sierra de Muriellos, almost overhanging the Lloredo stream.

Where exactly is it located?

Alcornocal de Boxo lies in the southeastern part of the Allande municipality, within the wider Protected Landscape of the Sierras de Carondio y Valledor. Its approximate coordinates are 43.277° N, 6.788° W. The forest itself consists of two compact clusters of the oldest specimens, spread across a steep, south-facing slope.

When and why was it protected?

The area was declared a Natural Monument (Monumento Natural) in 2002. The designation aimed to protect a unique ecosystem — not just the trees themselves, but also the accompanying flora and the microclimatic conditions that allowed the species to persist outside its typical range. Legal protection within the broader Sierras de Carondio y Valledor reserve further shields the forest's surroundings from development and land-use pressure.

What should visitors know before going?

Visitors should be aware that the terrain is steep and partly wild — reaching the oldest specimens means walking along a sloped hillside near the stream. The site will appeal mostly to botany enthusiasts and people interested in rare natural phenomena, rather than travelers looking for an easy scenic trail. Sturdy trekking footwear is recommended, since the ground can be damp and slippery, especially after rain, which is frequent in this region for much of the year.

Frequently asked questions

What is Alcornocal de Boxo? It is a natural monument protecting the most important and best-preserved cork oak forest in Asturias, located in the municipality of Allande.

Why is this place unusual? Cork oak typically grows in a warmer Mediterranean climate, yet it found suitable conditions here thanks to the high humidity and abundant rainfall of the Navia river basin.

When was it protected? It was granted Natural Monument status in 2002.

Where exactly is it located? On the southern slope of the Sierra de Muriellos, near the Lloredo stream, in the southeastern part of the Allande municipality, within the Protected Landscape of the Sierras de Carondio y Valledor.

Is the site easy to access? Not entirely — the terrain is steep, and the oldest trees grow in two clusters on a sloped hillside, so visitors should expect a demanding, if short, walk.