Due to its dimensions and the precious geological value, the Sima de San Pedro is considered unique in Europe. With a karstic origin, this spectacular hole in the ground is located in Oliete, south of the Sierra de Arcos, in Teruel. It is surprising not only for its dimensions, but also for the diversity of animals and plants that live there. A journey to the interior of the earth thanks to its 86 metres deep; to which we must add the 22 metres of the lake inside. It is also worth mentioning its 80 metres in diameter.
Both its location in a ravine and the presence of detrital sediments found on the outside have led to the conclusion that there was previously a karstic complex that shrank after collapsing on the caves.
On the other hand, the lagoon of the Sima de San Pedro gets its water from the ravine itself; as well as from the underground water it drinks from the Martín river. The height of the lake is 22 metres and it has more than 500,000 m3 of water.
Deforestation is the image of the surroundings of the Sima de San Pedro. However, on the access road there is one of the few specimens of Juniperus thurifera near the Martín river basin. As for the fauna, many birds take refuge in the Sima de San Pedro. For example, the rock pigeon, the red-billed chough and the rock sparrow, among others. In addition, up to seven species of bats live here. Fossils from the Jurassic period have been found in the area.
It is possible to observe the interior of the Sima de San Pedro from a footbridge that has been installed as a viewpoint to this long chasm. Thus, the more than 80 metres from the footbridge to the lake are not suitable for those who suffer from vertigo. Due to its conditions, it is a common focus of national and international speleology competitions.
What to see in the surroundings of Sima de San Pedro
The closest town to the Sima de San Pedro is Oliete, located in the Andorra-Sierra de Arcos region. After visiting this chasm in Teruel, a good plan is to walk through the streets of Oliete, a town of 350 inhabitants, where you can visit the Church of Nuestra Señora de la Asunción, from the 18th century, and its outstanding Mudejar bell tower.
Among all the things to see in Oliete, the arches that are found here, corresponding to the old fortified entrances of the village, are striking. They date from the Middle Ages and are three in number: the arch of Pilar, the arch of Santa Bárbara and the arch of the Santos Mártires. All of them are accessible and can be found by taking a walk through the streets of Oliete.
Another of the temples to point out is the hermitage of the Virgen del Cantal, built around 1660. It was built to honour an image of the Virgin that appeared in the area hidden under a cantal (rock in Aragonese).
The prehistoric heritage is also striking, as is the case of the Frontón de la Tía Chula. It is a group of cave paintings that were made between the Chalcolithic and the Middle Bronze Age. The paintings are located on a rock that has a hole through which, during the spring and autumn equinoxes, the sunlight filters. In this way, it is one of the oldest solar sanctuaries in the world, approximately 4,500 years old.
Other villages near Oliete that are also interesting to visit are Calanda and Híjar, both just over half an hour away by car. Here you will need to stop a little longer, as Calanda has a rich artistic and cultural heritage. One of the most representative archaeological findings of the town is the site of Camino de Albalate. It is an incredible mosaic that would confirm the theory that Calanda was an influential Roman villa.
The religious architecture of Calanda also occupies a significant place in the tour of the municipality. Amongst all the examples; some of the most significant are the temple of El Pilar, a baroque building that commemorates the Miracle of Calanda; the Church of Nuestra Señora de la Esperanza, a Rococo style construction from the 18th century; and the arch of San Roque, the old entrance gate to the town. The Calanda Peach is also famous from here.
At the same distance by road is Híjar. The most interesting thing is to walk through the streets and discover the local Jewish legacy; there are also two great monuments. On the one hand, the church of Santa María la Mayor, one of the most famous Mudejar temples in Aragon. It has been declared an Asset of Cultural Interest, whose construction began in the 14th century, although it was remodelled in later centuries in a Renaissance style.
On the other hand, the castle-palace of the Dukes of Híjar. With an Islamic origin, this fortress preserves a keep, a tower, the remains of the ducal palace and a central courtyard. You can also see the so-called Moorish tower, made of masonry.