The Almadén mine historically produced roughly one-third of all mercury ever used by humanity.
Mercury extraction at this location dates back over 2,000 years to Roman times.
The mines were once a royal monopoly, providing the mercury necessary to extract silver from American ores in the Spanish Empire.
The site contains the 'Castillete de San Teodoro', a metallic structure essential for vertical extraction, built in the early 20th century.
The mine includes the 'First Level' of underground works, which provides a safe, guided descent into the historical mining tunnels.
The site represents the 'Mercury Route', a transnational heritage network connecting Almadén to Idrija, Slovenia.
Cinnabar, the red ore found in these mines, is the primary source of the world's mercury.
The mining park occupies the historic Cerco de San Teodoro, a fortified mining precinct that protected the state-owned resources.
Almaden Mining Park is a UNESCO World Heritage site dedicated to the history of the world's oldest and most productive mercury mine. The park preserves the San Teodoro mining compound, showcasing centuries of industrial extraction technology. Visitors can descend into the 17th-century underground galleries to observe the geological formations and original mining environments. The site includes the Mercury Museum, which documents the chemical importance and global trade history of liquid silver. Exhibits display historic machinery, including steam-powered pumps and extraction shafts used throughout the site's history. The location reflects the socio-economic evolution of the Almadén region linked to the royal mercury monopoly. It serves as an open-air museum preserving the remains of mining architecture from the Renaissance period to the 20th century. The site remains a functional monument to European industrial heritage.
The viewing platform overlooking the San Teodoro shaft headgear (Castillete).
Wear comfortable, closed-toe walking shoes as the underground paths are uneven.
The temperature remains constant underground, so bring a light jacket even during hot summer months.
Reserve your underground tour slot in advance online, as capacity is limited for safety.
Do not attempt to walk through the industrial zones outside the guided tour paths for safety reasons.
Closed on Mondays throughout the year; occasionally closed for maintenance in the low season.
Hard hats provided for the underground tour must be worn at all times; do not touch historical machinery or structural supports.
