The eruption that created the Ulmener Maar was one of the most recent volcanic events in Central Europe.
The dry maar known as Jungferweiher is separated from the lake by a narrow ridge, though both were formed by related volcanic activity.
Archaeological findings suggest the volcanic activity was triggered by magma coming into contact with groundwater, causing a massive steam explosion.
The castle ruins overlooking the lake date back to the 11th century and belonged to the Lords of Ulmen.
The water in the Maar is considered oligotrophic, meaning it is low in nutrients and high in oxygen, which supports specific sensitive fish species.
Ulmener Maar is the youngest maar in the Eifel volcanic region, formed approximately 11,000 years ago during a phreatomagmatic eruption. It is unique for being a double maar complex consisting of the water-filled Ulmener Maar and the adjacent, dry Jungferweiher. The lake reaches a maximum depth of approximately 37 meters. It sits at an elevation of 460 meters above sea level. The site is part of the Volcanic Eifel Geopark, recognized for its geological significance. Walking paths circumnavigate the crater rim, providing views of the water and the surrounding volcanic terrain. Historical remnants of the medieval Ulmen castle ruins are located directly on the crater edge. The Maar is situated within the town limits of Ulmen, directly accessible from the urban area. It serves as a natural habitat for diverse aquatic flora and fauna.
From the Ulmen castle ruins looking down over the lake toward the forest canopy.
Wear sturdy hiking boots as the path around the crater rim involves uneven terrain.
Combine your visit with a walk to the Jungferweiher to see both parts of the volcanic complex.
Bring binoculars to spot birds of prey that frequent the crater rim.
Do not attempt to swim in areas not designated as public access points to ensure personal safety and ecological protection.
Stay on marked trails to prevent erosion of the crater slopes and protect local flora.
