Between stone and darkness, the smell of damp earth and memories of the past, a labyrinthine universe of corridors and cellars unfolds, whispering stories that are present in the collective memory of the people. Sculpted by hand and with patience, they create a fascinating underground world where history, architecture and winemaking tradition converge in a unique way.

In these "underground cities", time seems to stand still among the galleries dug centuries ago, many of them designed as cellars for the production and preservation of wine. In the days of smuggling, they were the perfect refuge to avoid royal taxes, and during the War of Independence (1808-1814), they were hideouts for Spanish guerrillas resisting Napoleon's troops. Some linked villages by secret passageways, creating a clandestine network that outwitted invaders. They also served as air raid shelters during the Spanish Civil War (1936-1939).

Castilla y León preserves numerous examples of great size and richness, although they are spread throughout the Iberian territory.

The journey can begin in Aranda de Duero, in the province of Burgos, where 135 underground cellars connect through 7 km of tunnels dug between the 12th and 18th centuries. At a depth of 9 to 12 m, the constant humidity necessary for the optimal conservation of the wine is maintained. The subsoil also offers wonders in Gumiel de Mercado: the Cerro del Castillo is home to a series of caves that are still in use. Further south, Vadocondes preserves a historic quarter with almost a hundred cellars and wine presses dating back to the 13th century, while in Zazuar the 17th century underground cellars under the houses are part of everyday life. Not far away, Moradillo de Roa stands out for its ethnographic ensemble "El Cotarro", made up of 157 cellars and seven cave wine presses, which have been awarded the prestigious Europa Nostra 2020 prize for their conservation. And in Sotillo de la Ribera, the Cerro de San Jorge has 86 wineries and 99 wine presses spread over 3 km of tunnels, many of which are privately owned.

In San Esteban de Gormaz, a town famous for its Romanesque architecture, there are 298 underground cellars, some still in use and others for sale, waiting for new owners. Nearby, in Atauta, a small village of barely sixty inhabitants, 141 structures have been active for more than eight centuries, restored by the inhabitants themselves.

The landscape changes as you enter Fermoselle, known as the "village of a thousand wineries", which has an underground network that dates back to the 10th century and connects galleries that today bear witness to its rich winemaking tradition. In El Perdigón, the cellars, dug into the clay, are grouped in three districts outside the city centre. Further north, in Morales del Rey, on the slopes of the hill overlooking the village, there are around 200 wineries, where winemaking is the main attraction for meetings of friends and neighbours. Cerecinos de Campos, Bretó de la Ribera and Bretocino also have underground cellars that keep alive the memory of a winemaking past.

Valdevimbre surprises with the popular architecture of its century-old wineries, many of which have been converted into restaurants that combine local gastronomy with the magic of its underground surroundings. Nearby, in the region of Los Oteros, the wineries of Pajares add another chapter to this rich tradition.

The journey continues to Mucientes, where the cellars of the 16th and 17th centuries form an educational space in the subway neighborhood of Cuarto de San Pedro, awarded in 2020 as Best Wine Tourism Municipality. In Rueda, the 15th century passages reach depths of 25 m, hiding the soul of this land of wines.

Baltanás proudly boasts the largest network of underground cellars in Spain, with 374 structures spread over six superimposed levels in the Cerro del Castillo. This monument to the splendour of 15th-century winemaking has been declared an Asset of Cultural Interest, thus consolidating its value in the national underground network.

In the Valencian Community, Utiel preserves almost 400 wineries, interwoven with the medieval fabric of its historic centre. In Laguardia (Álava), the density of "calados" is such that lorries are banned to protect the buildings. In places such as Borja (Zaragoza), Tomelloso and Valdepeñas (Ciudad Real), or Haro (La Rioja), underground cellars complete this map of hidden treasures, where the winemaking tradition finds refuge in the depths.

Visiting Spain’s tunnels is like stepping back in time. Each cave, each cellar, speaks to the ingenuity of those who tamed the land to safeguard their culture’s essence. Beneath streets and fields, these underground cities remain a living testament to a storied past that continues to enrich the present.