Mendiger Ley

Useful Information

Lavakeller, Eifel, Deutschland. Public Domain.
Location: Obermendig, northwest of the train station, Brauerstraße. A61 Köln-Ludwigshafen, exit Mendig, towards Mendig, follow signs Lava-Dome. Tickets for the cellars at the Lava Dome museum.
Open: Lava-Dome:
All year Tue-Sun, Hol 10-17:30.
School Holidays (RLP+NRW) daily 10-17:30.
All year Tue-Fri 13:30, Sat, Sun, Hol 12, 13:30, 15.
School Holidays (RLP+NRW) daily 12, 13:30, 15.
31-DEC, 01-JAN closed.
no restrictions.
Fee: Lava-Dome:
Adults EUR 7.50, Children (-16) EUR 5.50, Children (-1 m) free, Students EUR 6, Disabled EUR 6.
Families: Adults EUR 5.80, Children (-16) EUR 4.30.
Groups (15+): Adults EUR 6, Children (-16) EUR 5.50, Students EUR 5.
Reservation required.
Cellar: Adults EUR 5.50, Children (-16) EUR 4, Children (-1 m) free, Students EUR 4.60, Disabled EUR 4.60.
Families: Adults EUR 4.60, Children (-16) EUR 3.50.
Groups (15+): Adults EUR 4.60, Children (-16) EUR 3.50, Students EUR 3.50.
Reservation required.
Both: Adults EUR 9.50, Children (-16) EUR 7.50, Children (-1 m) free, Students EUR 8, Disabled EUR 8.
Families: Adults EUR 7.80, Children (-16) EUR 6.30.
Groups (15+): Adults EUR 8, Children (-16) EUR 7.50, Students EUR 7.
Reservation required.
Classification: SubterraneaRock Mine ExplainRoom and Pillar Mining basalt mines
Light: LightIncandescent Electric Light System
Dimension: VR=35 m, AR=2.8 ha, T=5-7 °C.
Guided tours: VR=35 m, AR=0.7 ha, D=60 min, St=156.
Photography: allowed
Accessibility: yes, elevator
Bibliography: J.J. Nöggerath (1841): Zirkon in der porösen Mühlstein-Lava von Niedermendig Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefaktenkunde, 696.
T. Wolf (1868): Die Auswürflinge des Laacher-Sees Zeitschrift der Deutschen geologischen Gesellschaft, Vol. XX, 1-78.
Address: LAVA-DOME, Brauerstrasse 1. 56743 Mendig, Tel: +49-2652-9399222. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


7,000 BP basalt mined by prehistoric man.
~0 first millstone mining in Roman times.


The basalt deposits near Mendig are a cooled lava flow of basaltic lava produced by the Laacher See volcano, just a few kilometres to the north. The eruption occurred only a geologically short time ago, 13,000 years ago. The first lava flows filled up the then existing valleys, later lava flows flowed over the resulting plain, reaching a thickness of about 30 m over a large area.

In the last 500,000 years, around 40 cinder cones were formed in the Eastern Eifel. The three largest eruptions were Riedener Kessel, Wehrer Kessel and Laacher See. The Laacher See volcano is not considered extinct and recently an increase in volcanic activity has been noted. This can be seen from a slight uplift and increase in CO2 production.


Engraving by Barthélemy Faujas de Saint-Fond, 1802, Niedermendiger Lavakeller, Eifel, Deutschland. Public Domain.
Postcard ca. 1900, Niedermendiger Lavasteingrube, Eifel, Deutschland. Public Domain.

The town of Mendig has a large number of interconnected cellars northwest of the railway station, in an area of about 0.3 km². The labyrinth was originally created by mining basalt at a depth of 32 m. The basalt was mainly quarried in the form of millstones. It was already quarried in the region by the Romans for this purpose in ancient times. In the Middle Ages, millstones were the basis of the town's wealth and were exported all over Europe. While the Romans still quarried mainly on the surface, in the Middle Ages mining followed the most suitable basalt underground. Another reason for underground quarrying was that the basalt near the surface is of lower quality due to weathering. Thus, the basalt layer was extensively quarried about 30 m below the surface, but a 10 m thick cover remained. The quarrying was carried out in the classical room and pillar method, i.e. pillars were left standing at regular intervals to support the ceiling. Depending on how you look at it, the result is a huge room with many pillars or an extensive labyrinth of corridors.

It soon became apparent that the mine had a constant temperature. However, this temperature was slightly different in different cellars, between 7 °C and 2 °C. The 7 °C corresponds approximately to the temperature of the rock. The colder cellars act like a cold trap, the cold winter air flows in through openings from the surface and the temperature is then maintained all year round. These are ideal conditions for storing beer, and so the cellars were used as beer cellars from the beginning of the 19th century. Around 1900, there were 28 breweries in Mendig that stored their beer supplies in the lava cellars. The beer was exported far and wide, including to Cologne. The development of the railway at the end of the 19th century was helpful.

The town of Mendig is a centre of the Geopark Vulkaneifel. Three sights linked to volcanism can be found here in a very small area. A modern museum has been built under the name Lava Dome, and combined with the Lava Cellars and the neighbouring Museumslay. The museum contains many panels and models explaining the basic mechanisms of volcanism, especially the rather atypical Eifel volcanism. There is even a model that demonstrates a volcanic eruption. It offers many interactive exhibits and is especially interesting for children. Of particular interest is a special broadcast by the Reginal radio station, which reports live from the eruption of Lake Laach. As already mentioned, the volcano is not extinct, and a new eruption is unlikely but quite possible. The damage would be astronomical, probably also the loss of life.

The Museumslay - a lay is a historic basalt quarry - is a kind of open-air museum showcasing the techniques and tools used to mine the basalt. The grounds are park-like and freely accessible. It is a good place to visit if, for example, you are waiting for the guided tour of the lava cellar.