Location:
Map
Open: May-
Oct
Nearest town:
Werfen- 3 miles (5 km)
Transport:
Car or train from Salzburg to Werfen than
a bus to the car cable
Official
site
Eisriesenwelt, which translates from German as "World of the Ice Giants," is the largest accessible ice cave in the world. This natural wonder is a labyrinthine system of limestone and ice formations, renowned for its breathtaking frozen landscapes that evoke a mythical, otherworldly realm. Located in Werfen, Austria, approximately 40 km south of Salzburg, the cave is embedded within the Hochkogel mountain in the Tennengebirge section of the Alps, at an elevation of about 1,656 meters (47°30′11″N 13°11′25″E). It attracts around 200,000 visitors annually, offering a glimpse into a frozen subterranean environment that remains below freezing year-round, even in summer. The cave's name draws inspiration from Norse mythology, particularly the Edda saga, reflecting the gigantic ice structures that dominate its interior. Locally, it was once feared as a "gateway to Hell" due to the howling winds and icy mists emanating from its entrance, a belief that deterred exploration for centuries.
The formation of Eisriesenwelt dates back approximately 100 million
years to the late Tertiary period, when tectonic shifts during
mountain-building processes (Alpine orogeny) created initial crevices
and fissures in the limestone rock of the Tennengebirge karst plateau.
Over millennia, chemical dissolution by rainwater and mechanical erosion
by the Salzach River widened these fissures into expansive cavities and
passageways. The cave system continued to evolve during the
Pleistocene's Würm glaciation, shaping the broader mountain range.
Unlike static caves, Eisriesenwelt is classified as a dynamic ice cave,
featuring vertical chasms and corridors that connect lower entrances to
higher openings, functioning like a natural chimney for airflow.
The
ice formations result from a seasonal cycle: In winter, warmer air
inside the cave rises, drawing in cold external air that cools the lower
sections below 0°C (32°F). In spring, meltwater from thawing snow seeps
through rock fissures into this supercooled environment and freezes,
building up layers of ice. During summer, cold air from deeper within
the cave blows outward, preventing melting and preserving the ice. This
process creates stalactites, stalagmites, frozen waterfalls, columns,
and expansive ice embankments. The oldest ice layers are estimated to be
around 1,000 years old, and the cave is still actively growing as new
water carves additional passageways. Scientific research, including ice
core studies, has revealed low ion content in the ice and distinct
cryocalcite layers, providing insights into past climates. While much of
the cave system has stabilized due to reduced water flow in some areas,
the Alpine location ensures ongoing development in others.
Eisriesenwelt spans a total length of over 42 kilometers (about 26
miles), making it the world's largest ice cave system. However, only the
first kilometer (0.6 miles) is perpetually covered in ice and open to
the public via guided tours; the remaining 41 kilometers consist of bare
limestone and are reserved for scientific exploration. The cave descends
about 400 meters underground at its tourist endpoint.
Notable
features include:
Posselt Hall: A large chamber with the central
Posselt Tower, a prominent ice stalagmite marking the extent of the
initial 1879 exploration.
Great Ice Embankment: A massive
25-meter-high (82-foot) ice wall, representing the area of maximum ice
accumulation, which visitors must ascend via steps.
Hymir's Castle:
Named after a Norse giant, this section features intricate stalactites
forming "Frigga's Veil" (resembling a curtain) and the "Ice Organ"
(pipe-like formations).
Alexander von Mörk Cathedral: A vast dome
honoring the early explorer, with dramatic ice sculptures.
Ice
Palace: The tour's climax, located 1 km in and 400 meters underground,
showcasing frozen waterfalls and ethereal ice designs.
Other
elements include the Sturmsee (a frozen lake) and various side branches
like the dry Wimur passage. The cave's interior is illuminated solely by
carbide lamps during tours, enhancing the shadowy, mystical ambiance
without electricity.
For centuries, locals in Werfen knew of the cave's entrance but
avoided it, convinced it was an entrance to the underworld due to the
cold winds and fog billowing out. The official discovery occurred in
1879 when Anton von Posselt, a Salzburg naturalist, ventured 200 meters
inside, marking his turnaround point with the "Posselt-Kreuz" (Posselt
Cross) due to steep ice and limited equipment. He published his findings
in a mountaineering journal in 1880, but the cave was largely forgotten.
Rediscovery came in 1912, led by Alexander von Mörk, a speleologist and
founder of the Salzburg Section of the Association for Speleology. With
companions like Benno Pehany, Erwin Angermayer, and Herrmann Rihl, they
overcame the Great Ice Wall using carved steps and better gear,
exploring horizontal sections including the Sturmsee and naming the cave
Eisriesenwelt. Expeditions paused during World War I, where Mörk died in
1914; his ashes are interred in a niche in the cave's cathedral.
Post-war exploration resumed in 1919 with figures like Walter von
Czoernig-Czetwertynski and the Oedl brothers, who mapped 18 kilometers
by 1920, including domes like the "Dom des Grauens" (Dome of Horror).
Connections to nearby caves like Sulzenofen were investigated.
By 1920, the Forscherhütte (Explorer's Hut) was built, establishing mountain routes and attracting the first tourists, turning the cave into a "world sensation." In 1924, wooden walkways were added for safety. The Dr. Oedl House followed, along with paths from Werfen and Tenneck. A major advancement came in 1955 with the construction of a cable car (Austria's steepest gondola), reducing the ascent time from 90 minutes to just 3 minutes. Today, the cave is owned by the National Austrian Forest Commission and leased to the Salzburg Association of Cave Exploration since 1928, which manages operations and shares revenue. Exploration beyond the tourist zone continues for scientific purposes.
Eisriesenwelt is open seasonally from May 1 to October 31 (as of
2025), daily from 8:30 a.m. to 3:00 p.m., with visitors advised to
allocate about 3 hours for the full experience. All visits are via
guided tours lasting approximately 75 minutes, conducted in groups with
multilingual guides covering geology, ecology, glaciology, and history.
Tours start at the entrance, proceed through key features, and loop back
out, involving about 1,400 steps (700 up and 700 down) over 1.5 km.
Photography is prohibited inside to preserve the experience.
Accessibility requires physical fitness due to the terrain: From the
parking lot, it's a 20-minute walk to the cable car, a 3-minute ride up,
and another 20-minute hike to the entrance (over 400 feet elevation
gain). The entrance is 124 meters above ground level. For those
preferring a challenge, a footpath over alpine terrain bypasses the
cable car. The cave is kid-friendly but demanding due to slippery ice;
it's also dog-friendly, though suitability varies. Warm clothing, sturdy
shoes, hats, and gloves are essential, as temperatures hover around 0°C
(32°F). Online tickets offer discounts and timed slots (30-minute
windows), with group rates for 20+ people and school trips requiring
reservations. For current pricing, visitors should check the official
website, as rates may vary.
Tips for visitors include arriving early
to avoid crowds, preparing for the physical demands, and considering the
cave's closure from November to April due to weather. Wildlife is
minimal in the icy tourist areas but may exist deeper in the limestone
sections.
What sets Eisriesenwelt apart is its blend of natural artistry and human history: the interplay of light from handheld lanterns on ice sculptures creates a haunting, underworld vibe, true to its "gateway to Hell" moniker. As a living geological site, it offers insights into climate history through its ice layers and continues to inspire awe as a testament to nature's sculptural power. Its status as a protected site underscores its ecological value, with no flora or fauna in the frozen zones but potential biodiversity in deeper, warmer areas. For adventurers, it represents a rare opportunity to step into a frozen time capsule in the heart of the Alps.