In 1927, it was officially opened as an electrically illuminated show cave, spanning a length of 174 meters and comprising three substantial chambers, one of which contains dripstones.

The incident unfolded when one of the cows from Mellmann's herd strayed and fell through a thin layer of earth into a cavity.

Over three years, three Polish miners undertook the task of excavating into the mountain using a hammer and chisel as their tools and oriented themselves with a compass.

After covering 45 meters, they made a remarkable discovery: an unknown natural cavity adorned with dripstones, which they named the chapel.

To create a passage, a substantial amount of material, totaling 300 cubic meters, including basalt, clay soil, tree trunks, and animal bones, had to be transported out.

During the excavation process, numerous animal bones from dogs, goats, cattle, donkeys, cats, and pigs were discovered, which underwent thorough examination and dating by Fritz Drevermann, a professor of geology and paleontology who also served as the rector of the Johann Wolfgang Goethe University in Frankfurt am Main, Germany.

[3] In 1911, during the excavation of the rubble cone in the cave, a skull purportedly belonging to a fossil human was reported to have been discovered.

[2] During World War II, it temporarily served as an air raid shelter for the residents of Steinau.

[9] In autumn 2011, efforts were made to construct a new hut with facilities for cave visitors, including a toilet suitable for the disabled.

This cave, which came into existence about 2.5 million years ago, is a rare geological feature in the Spessart region, with red sandstone and basalt predominating.

The formation of the Teufelshöhle involved the influx of lime-saturated waters, including contributions from the Ulmbach stream, which entered through fine cracks and fissures within the hanging basaltic rocks.

Additionally, the presence of underground watercourses with whirlpools contributed to the formation of cavities, such as the Great Dome.

[2] The temperature within the cave maintains a constant range of around eight to nine degrees Celsius, and the humidity consistently exceeds 80 percent.

An opening in the ceiling connects it to the outside world through a shaft, the former Devil's Hole, allowing partial sunlight to penetrate the cave.

[7] The distinctive curvature of the cave was formed due to the whirlpool effect created by the convergence of two water veins, whose remnants are still visible.

The chamber's walls feature bright, shiny lime sinter coatings, and the horizontal layers of different rock levels are visible.

The climatic chamber represents the lowest point within the cave, situated 34 meters beneath the Earth's surface.

[2] This passage-like room offers air that is nearly devoid of dust, with humidity levels at an impressive 98 percent, higher than in other parts of the cave.

A bench facilitates individuals with specific medical conditions, including whooping cough, asthma, bronchial diseases, and, according to recent findings, neurodermatitis, as part of their treatment.

[2] Continuing from the Great Dome, a short corridor on the left side of the entrance gallery leads to the chapel, which is considered the most beautiful room in the cave and extensively adorned with sinter deposits.

A short staircase with a turnaround point ascends within the chapel, leading to a small passage that cannot be entered.

These bats enter the cave in the autumn through the Teufelsloch (Devil's Hole) in the Great Dome to hibernate undisturbed.

[2] Within the Teufelshöhle, a unique plant community referred to as "lamp flora" has developed in the presence of artificial lighting.

This flora primarily consists of algae, mosses, fungi, and fern plants that can establish themselves in the vicinity of the light sources.

These plants typically exhibit stunted growth forms that would struggle to survive in complete darkness without the aid of artificial lighting.

The plants are unevenly distributed and depend on the spores that enter the cave through water seepage from the Earth's surface via cracks and fissures.

However, in the Great Dome, the largest chamber in the cave and the only one connected to the outside world, distinctive plant growth has occurred due to drafts.

[1] These tours take visitors through various sections of the cave via easily accessible paths and stairs, with a duration of approximately 30 minutes.

The route includes ascending some stairs to reach the climatic chamber and then returning to visit the chapel and the beehive formation.