Layer of time · 450 million years ago – present
Before us
Before people, the Alto Tajo was a cold sea near the south pole, a forest buried by ash, a plain of red rivers, salt lagoons, and a tropical ocean; later the earth buckled and the Tagus carved through it. Each era left a rock that can still be seen today.
A selection of traces related to this era. Dates correspond to the historical layer; a location may have other origins, transformations, and subsequent uses. Contested attributions are noted in their guides.
Stories of this layer
- Before us: the long time of stones
Cold seas, stone forests, volcanoes, red rivers, a tropical sea and a river cutting the plateau: Alto Tajo’s history before people, in plain words.
Where its trace endures
Laguna de Taravilla: an 11,000-year-old natural tufa dam
Taravilla
Barranco de la Hoz: the red canyon of the Gallo River
Corduente, VentosaCuevas Labradas folds: rocks folded like an accordion
Cuevas Labradas
Marine fossil site at Cuevas Labradas
Abandoned meander of Hoya de la Parra (Taravilla)
Taravilla
Checa Dropstone: a boulder dropped from an iceberg 440 million years ago
ChecaCheca Graptolites: Fossils That Look Like Writing
Checa
The Aguaspeña of Checa: a living rock growing 4 cm a year
ChecaPoljé del Cubillo (Checa): a closed karst valley
Checa
Las Quebradas: the little enchanted city of Chequilla
Chequilla
Orea Stone Run: a boulder river you can hear
Orea
Corridors of Peñas Rubias: the enchanted city of Orea
Orea
Laguna de la Salobreja (Orea): a saltwater lagoon in the mountains
Orea
La Escaleruela: the stepped tufa waterfall of Zaorejas
Zaorejas
Sima de Alcorón: Descending 63 Metres to the Heart of the Paramera
Villanueva de Alcorón
Enchanted city of Hoya del Espino (Peñalén)
Peñalen
Salto de Poveda: The Largest Waterfall in Alto Tajo
Poveda de la Sierra, Taravilla
Hundido de Armallones: the rock collapse that dammed the Tagus
Armallones, Ocentejo
Valle de los Milagros: red sandstone towers in Riba de Saelices
Riba de Saelices
Ancient volcano of Orea: 270-million-year-old dacites
Orea
Fuentelsaz Stratotype: a global geological reference standard
Fuentelsaz
Fossil forest of Rillo de Gallo: a 300-million-year-old Pompeii
AragoncilloTormo de Mochales: The Rock Tower of the Mesa Valley
MochalesEl Huso: the stone monolith of Barranco de la Hoz
Corduente
Fossil ray traces of Esplegares, from the Lower Jurassic
EsplegaresPeñalén folds: a tropical sea crumpled by the earth
PeñalenVariscan folds between Checa and Orea: the oldest rock wrinkles
ChecaFossil waves of Padilla del Ducado: a 240-million-year-old seabed
AnguitaTriassic rivers in Rillo de Gallo: current traces from 240 million years ago
Rillo de Gallo
Laguna Grande de El Tobar (Beteta): a lake with saltwater at the bottom
Beteta
Type locality of aragonite: the mineral named after Aragon
Molina de AragónThe era on the map
450 million years ago – present
Before us
Before people, the Alto Tajo was a cold sea near the south pole, a forest buried by ash, a plain of red rivers, salt lagoons, and a tropical ocean; later the earth buckled and the Tagus carved through it. Each era left a rock that can still be seen today.
Upper Palaeolithic – Bronze Age
First traces
Before villages there were rock shelters. In the Cueva de los Casares, Upper Palaeolithic hunters engraved horses, stags, and human figures on the cave walls; at the Gallo shelters and Peña Escrita, later peoples left schematic painted signs on the stone.
7th – 1st centuries BC
Celtiberian hillforts
Settlements perched on spurs with defensive ditches, dry-stone ramparts, and fields of chevaux-de-frise stones. El Ceremeño, Peña Moñuz, and Castil de Griegos tell how people lived, defended themselves, and worked iron in Celtiberia before Rome.
1st – 4th centuries AD
Rome in the canyon
A double-tiered aqueduct in Zaorejas, perhaps linked to a mansio on the road between Laminium and Caesaraugusta, and the iron mining galleries of Cueva del Hierro: Rome arrived in the Alto Tajo in search of water, transport routes, and metal.
1129 – 15th century
The frontier and the Señorío
Borderland between Castile and Aragon, the Señorío de Molina was almost an independent kingdom: castles, watchtowers, a Cistercian monastery, and the salt pans of Armallá already recorded in the 12th-century charter of Manrique de Lara.
16th – 19th centuries
Salt, iron and timber
The Crown took control of the salt pans, ironworks drove tilt hammers with river water, and every winter thousands of logs floated down the Tagus toward Aranjuez guided by timbermen.
1860 – 1960
Resin, hooks and pastoral shelters
The century when the mountains sustained everyday life: resin tappers scoring pine trunks, shepherds sheltering under juniper-thatched chozones, lime kilns smoking beside villages. A world that faded within a single generation.
1936 – 1939
The frontline on the river
The canyon formed part of the Civil War frontline: positions atop the cliffs, guarded river crossings, and bunkers. The memory of the war also encompasses the Molina guerrillas, forestry labor, and local families. The Upper Tajuña valley traces this history on the western flank.
1950 – present
Villages that emptied
Reservoirs severed the river to floating timber, motor trucks retired the muleteers, and villagers migrated to Madrid, Valencia, or Barcelona. Some hamlets were abandoned completely; others endure with a handful of year-round residents.