Location: 25 km North of Graz
Info: (03127) 2580
Open: Apr- Oct: 9am- 4pm daily
The Lurgrotte Caves, located in the Tannenben karst region of Styria, Austria, approximately 16 km north of Graz, represent the largest active water-flowing dripstone cave system in the country and one of the most significant karst formations in the Eastern Alps. Spanning nearly 6 km in length with a depth of -273 m, the cave crosses the Tannenben massif and features two independently managed entrances: one in Semriach (eastern side) and one in Peggau (western side). Formed in limestone rock dating back 350–400 million years, the cave maintains a constant temperature of 10°C and humidity above 95%, hosting unique geological formations, underground streams, and biodiversity including bats. Discovered in the late 19th century, it has a rich history of exploration marked by dramatic events like floods and rescues. As a natural monument, it offers guided tours showcasing stalactites, stalagmites, and vast chambers, attracting visitors for its subterranean beauty and adventure opportunities. While traversable end-to-end until 1975, floods have limited access, but recent renovations, including a 2025 lighting upgrade at Peggau, enhance safety and visibility.
The Lurgrotte's human history dates to the Paleolithic era, with
archaeological evidence including a reindeer bone dated to around 52,000
years ago bearing tool marks, indicating Neanderthal presence, and cave
bear fossils from 20,000 years ago. The cave's modern discovery occurred
on April 1, 1894, when Italian speleologist Max Brunello and a team
explored from the Semriach entrance, revealing its lower sections
despite initial blockages at Peggau. A notable incident followed on
April 29, 1894, when seven explorers were trapped for nine to ten days
by a flash flood; their rescue, involving over 1,000 workers, miners,
and divers, was authorized by Emperor Franz Joseph I after a local
priest's intervention.
Exploration advanced in the early 20th
century: the Austrian Tourist Club surveyed over 1 km in 1905, and in
the 1920s, Hermann Mayer and his father developed the Peggau section,
blasting a connection on November 26, 1924. The first complete traversal
from Semriach to Peggau occurred on February 13, 1935, taking 18 hours
over 5.5 km with boat assistance. Tragically, on May 23, 1926, explorer
Leopoldine Fuhrich fell to her death, commemorated by a plaque. The cave
opened as a show cave in 1933, with guided tours starting in 1957, but a
major flood in 1975 destroyed infrastructure, halting full crossings and
leading to Styria's withdrawal; Peggau municipality assumed management
with association support. Further floods, like in 2014, prompted a
retention basin and warning system. Auctions in 1927 preserved it as a
local asset, and during WWII, it served unspecified roles, but post-war
renovations included electric lighting. As of 2025, the Peggau entrance
features a renovated LED lighting system completed in phases from 2020,
with the final phase in May 2025, emphasizing conservation.
Geologically, the Lurgrotte is a classic karst cave formed 3–4 million years ago through the dissolution of Devonian-era limestone (350–400 million years old) by acidic water, enlarging cracks and creating passages via erosion from sand and stones. The rock, part of the Graz Highlands uplift, includes metamorphic marble colored by minerals like lead and iron, forming organic-like structures. The system acts as a three-level drainage for the Tanneben plateau, with hydrology involving the Lur River (entering at Semriach) and Schmelz River (exiting at Peggau), though sources remain partially unmapped—dye tracing shows complex connections, especially during high water. The cave's active water flow contributes to ongoing formation of dripstones, growing at about 1 mm³ per year, with Uranium-Thorium dating limited by the cave's age and protected status. Flash floods pose risks, mitigated by modern systems, and the constant 10°C temperature with 97% humidity supports unique microenvironments.
The Lurgrotte boasts stunning dripstone formations, including stalactites (ceiling-hanging), stalagmites (floor-rising), and columns where they merge. Highlights include the "Prince" stalactite (3.7 m tall), the 40-ton Giant Stalactite (thickest known in any cave), and the colorful "Baldachin" dripstone. Vast chambers like the Big Dome (120 m long, 80 m wide, 40 m high—one of Central Europe's largest) contain cave bear bones and swirl pots. Other features: the "Three Peaks" honoring Brunello, Crocodile Gorge, Siegeshalle with 1975 flood marks, and a cave bear skeleton display. The system hosts small fauna like cave woodlice and 6,000–7,000 bats (12–14 species) hibernating October–April. Infrastructure includes bridges, walkways, and a 2025-upgraded LED lighting system at Peggau (810 fixtures, 10 km cables, remote-controlled via Wi-Fi), using cooler tones to highlight textures while curbing lamp-flora growth. The Schmelzbach stream adds dynamic water elements, with high-water connections creating immersive experiences during tours.
As Austria's largest accessible underground system open to the public, the Lurgrotte holds profound geological, historical, and cultural value, illustrating karst processes and prehistoric human/cave bear habitation. Its dramatic exploration history, including the 1894 rescue, underscores human ingenuity and risks in speleology. Ecologically, it supports bat colonies and rare cave species, serving as a natural monument for conservation. Touristically, it draws over visitors annually to Styria, boosting local economy via adventure and educational experiences. Recent 2025 renovations promote sustainable tourism with energy-efficient lighting, aligning with climate goals. The cave's dual entrances foster regional collaboration, and its legends (e.g., trapped explorers) add folklore appeal, making it a key site for understanding Alpine karst heritage.
The Lurgrotte operates via two entrances with separate management,
offering varied tours year-round, though subject to weather and water
levels. As of 2025:
Locations: Semriach entrance (Lurgrottenweg,
8103 Semriach); Peggau entrance (Lurgrottenstraße 1, 8120 Peggau). Both
are 25 km north of Graz, accessible by car, bus (RegioBus Graz-Nord
stops at Peggau), or train.
Opening Hours:
Peggau:
April–October, daily guided tours at 10, 11, 12, 13, 14, 15 (July
5–September 7 confirmed; pre/post-season variable). Winter adventure
tours by appointment.
Semriach: Similar April–October schedule; check
for weekends/holidays. Both close during high flood risk.
Tour
Options:
"Prince" Tour (1 hr, 1 km): Lit path to Prince stalactite;
suitable for families.
"Blocksberg" Tour (2 hr, 2 km): Unlit sections
with flashlights; requires surefootedness.
Adventure Tour (5–7 hr,
4–4.5 km, winter): Full traversal with gear (helmets, lamps, overalls);
involves climbing/rappelling.
Tours in German/English; book groups in
advance.
Accessibility: 300+ steps; not
wheelchair/stroller-friendly. Dogs allowed at Peggau (leashed/muzzled).
10°C inside—wear jackets/sturdy shoes; high humidity means damp
conditions.
Tips from Visitors: Arrive early to avoid crowds; tours
are informative with great lighting/music. Refreshing cool air noted;
suitable for mobility aids like rollators in parts. Overall 4.8/5 rating
on TripAdvisor (60+ reviews), praising guides and formations.
Contact: Peggau: lurgrotte@gmx.net; Semriach: Similar via website. Check
https://lurgrotte.com for updates, as floods may cancel tours.