Cueva Negra, Montanejos

Cueva Negra is one of the standout natural attractions near Montanejos, a small town in the province of Castellón best known for its thermal springs. The cave sits just above the Fuente de los Baños, the spot where water flows year-round at a constant 25°C, drawing visitors from across Spain. For anyone exploring Montanejos, Cueva Negra is a natural extension of that visit — a chance to pair a scenic walk with a direct encounter with the region's geological and human history.

How do you get to Cueva Negra?

A hiking trail starts near the town center of Montanejos, close to the Fuente de los Baños, and leads up to the cave in roughly 45 minutes. The path winds along the rocky terrain of the Mijares river valley, passing views of nearby ravines and the vegetation typical of inland Comunidad Valenciana. No technical skill is required — the trail is considered accessible to nearly all age groups, making it a popular choice for families as well as more seasoned hikers. Sturdy footwear is recommended, since parts of the route cross uneven, rocky ground.

What will you find inside?

The cave entrance alone is striking: a mouth measuring 26 by 10 meters, one of the largest cave openings in the region. Beyond it opens a massive chamber covering around 2,300 m² with a volume of about 40,000 m³, placing Cueva Negra among the largest caves of its kind in Comunidad Valenciana. The dark coloring on the ceiling, which gives the cave its name ("Black Cave"), comes from soot left by fires lit by the people who once inhabited it — clear evidence of human presence in prehistoric times. Archaeological remains found inside point to a Neolithic settlement, and this significance has earned the cave official recognition as a Cueva de Especial Interés (Cave of Special Interest) in Comunidad Valenciana. Beyond its archaeological value, the cave is also home to invertebrate fauna that attentive visitors may spot during a visit.

Local oral tradition holds that Cueva Negra has a hidden passage connecting it to the nearby Barranco de la Maimona ravine, at a spot known as Ventana del Caballo ("the Horse's Window"). Despite repeated investigations by an experienced speleology group from Castellón, this connection has never been confirmed — the legend remains part of local folklore, adding an extra layer of intrigue to the site.

When is the best time to visit?

Spring and autumn are the best seasons to visit Cueva Negra, when temperatures in the Alto Mijares area are mild and the trail hasn't yet been baked by summer heat. In summer, an early morning start is advisable, since much of the walk offers little shade. In winter the cave and trail remain open, though it's worth checking conditions beforehand, as rain can make the rockier stretches slippery.

Frequently asked questions

Is visiting Cueva Negra free? Yes, access to the cave and the trail leading to it is free and doesn't require advance booking.

How long does the whole visit take? The hike itself takes about 45 minutes each way; allowing time to explore the cave and return, plan for a total of 2 to 3 hours.

Is the trail suitable for children? Yes, it's considered accessible to nearly all age groups, though trekking shoes and reasonable fitness are recommended given the uneven terrain.

Can I combine the cave with a swim at Fuente de los Baños? Absolutely — most visitors pair the cave visit with a walk or a dip in the nearby thermal springs, rounding out a full day in Montanejos.