Heritage of Mercury: Almadén and Idrija

From the Heritage of Mercury: Almadén and Idrija World Heritage inscription:

The property includes the mining sites of Almadén (Spain), where mercury (quicksilver) has been extracted since antiquity, and Idrija (Slovenia), where mercury was first found in AD1490. The Spanish property includes buildings relating to its mining history, including Retamar Castle, religious buildings and traditional dwellings. The site in Idrija notably features mercury stores and infrastructure, as well as miners’ living quarters, and a miners’ theatre. The sites bear testimony to the intercontinental trade in mercury which generated important exchanges between Europe and America over the centuries. Together they represent the two largest mercury mines in the world, operational until recent times.

Almaden: World Heritage City
Almadén: World Heritage City


There are two sites in two different countries that are part of this world heritage site. Almadén, which is in Spain, and Idrija, which is in Slovenia.

I visited the property in Spain and this post will deal with visiting the mine in Almadén.

NOTE: There is no risk of mercury of poisoning when visiting this mine. Mercury in its liquid elemental form is very dangerous. However, you will not see any silverly liquid inside the mine. The Mercury is in the form of Cinnabar, which is a red mineral created when mercury bonds with sulfur to create Mercury Sulfide (HgS). The only place you will see liquid mercury is in the visitor center, behind glass.

If you look at a map of the World Heritage Sites in Spain, Almadén sort of sits by itself, at least a 2-hour drive away from any other world heritage site. You could visit on a road trip from Madrid to Seville, but otherwise, you will probably have to make a special trip to visit. I drove out of my way to visit when going from Trujillo to Madrid.

Many people shy away from industrial heritage sites, but they are my favorite types. Learning how the items which made our modern world are an important part of our heritage, and visiting places like Almadén are an important part of that history.


View of how the Almadén mine operated before mechanization
View of how the Almadén mine operated before mechanization

The mine of Almadén date back to the Roman era when the red mineral cinnabar was found there. The Romans mined the mineral to use as a vermillion colored dye and as makeup, not knowing that mercury was one of the elements which made the mineral.

During the Moorish conquest of Spain, the mine continued its operation. The city of Almadén gets its name from the Arabic word for “mine”. It was during the Islamic period that mercury, in its elemental liquid form was first harvested from the ore.

After the Reconquista, the mine grew in importance as the mercury was a vital part extracting silver from silver ore. The mercury was shipped to the new world as ballast in ships and used in Spain’s colonial silver mines.

In 1645 the mines were acquired by the Spanish Crown due to their strategic importance and prisoners were sentenced to work in the mines to increase production.

The mine was active for centuries with modern mining techniques being adopted in the 20th Century. The mine eventually closed for environmental reasons in 2002 and the mine was reopened to visitors in 2006.

Almadén was given world heritage status along with the mercury mine of Idrija in Slovenia in 2012.

What to See and Do

Modern processing equipment in Almadén
Modern processing equipment in Almadén

Mercury Mine Tour
The primary attraction is the visitor center, mine tour, and Mining Interpretation Center at the mining park.

The tour begins in the visitor center and will take you into the top 50m of the mine, which is the oldest part of the mine. While the mine is over 500m deep and has over 290km of tunnels, only a small fraction of that is available to the public. Everything under 50m has been flooded.

The tours are usually only given in Spanish. If you do not speak Spanish, you can go along on the tour to see the mine, but much of the explanation will be lost.

At the end of the tour, you can visit some of the above-ground facilities and the Mining Interpretation Center

The entire tour takes about 2.5 hours.

Wear closed shoes and be prepared for lower temperatures inside the mine. You should consider wearing a light jacket and long pants.

Miners Hospital of San Rafael

Miners Hospital of San Rafael
The Miners Hospital of San Rafael

Located in the town Almadén is the minders hospital. It is part of the world heritage site and your entrance to the mine will also give you access to the hospital. While the hospital is available to visit, there are no guided tours provided.

Photography Tips

There is obviously no natural light when you are inside the mine. You will either have to use a flash or have your ISO settings on your camera set very high. Many of my images in the mine were taken at ISO 12,000-25,000.

Ask at the visitor center about taking a tripod into the mine as it probably will not be allowed.

Plaza del Toro

Plaza del Toro in Almadén
Plaza del Toro in Almadén

While not technically part of the world heritage site, the Plaza del Toro in Almadén is worth a visit. It is located in the middle of the town and the tourist information center is located inside it. There is a bullfighting museum inside as well which celebrates the history of bullfighting in Almadén and in Spain.

Operating Hours

The mine is open Tuesday to Sunday, and it is closed on Mondays.

It is open from From 10:00 AM to 2:00 PM and then from 3:30 PM to 6:30 PM. Keep in mind that many attractions in Spain close in the afternoon for siesta.

Where to stay

You can reach Almadén on a day trip from as far away as Madrid or Seville if you are willing to spend much of the day driving.

You will probably want to stay overnight in Almadén if your objective is to visit the mine. There are some hotels in Almadén where you can stay overnight.

The only liquid mercury you will see in Almaden, behind glass inside the visitor center
The only liquid mercury you will see in Almaden, behind glass inside the visitor center

How to get there


Almadén lies midway between Madrid and Seville. It takes 2 hours and 45 minutes to get from the Seville Airport (SVQ), and 3.5 hours to get from the Madrid Airport (MAD).

By Car

Almadén is most accessible by car. It is connected to the rest of Spain by the N-502 highway. The town and the mine are quite easy to find on most mapping programs like Google Maps.

Public Transportation

Almadén itself does not have a train station, however, there is a train station about 6 miles (10km) away outside of the town of Almadenejos. The train station is labeled as Almadenejos-Almaden. It is a 15-minute taxi ride from the train station to town and will cost under €10.00.

You enter the mine vertically by elevator, but you leave it horizontally by rail
You enter the mine vertically by elevator, but you leave it horizontally by rail


Age 15-64: €14.00
Age 65+: €12.00
Age 4-15: €11.00

You can purchase tickets on the official website, or at the visitors center.


The climate in Almadén is quite mild. Inside the mine expect temperatures around 10-15C (50-60F) regardless of what the conditions are outside or the season. It will seldom snow or freeze in Almadén.

Gary Arndt
Gary Arndt

Gary began traveling the world in 2007. His travels have taken him to over 200 countries and territories and 400 UNESCO World Heritage Sites.

He is a 3x Lowell Thomas Award winner and a 3x North American Travel Photographer of the Year.