Blautopf - Blauhöhlensystem
Region: Swabian Alb / Blaukarst
Location: Blaubeuren, Baden-Württemberg
Length / development: 18.149 km total system (10/2024); historic submerged route ~1.25 km to Mörikedom, Speleonaut to ~1.8 km
Depth / underwater: Blautopf basin 20.6 m; submerged cave profile varies
2026 status: RESEARCH ONLY / SENSITIVE
Early / notable explorers: Hasenmayer began systematic exploration in 1961; Mörikedom reached 1985; later Arge Blautopf/HFGOK/Blaukarst teams.
KCore note: Germany's iconic cave-diving system. Modern dry entrances and shafts transformed exploration, but underwater research remains central.
Aachtopf / Aachhöhle - 'Schwarze Donau'
Region: Swabian Alb / Donau-Aach
Location: Aach, Baden-Württemberg
Length / development: Complex active system; exact total changes with ongoing exploration
Depth / underwater: multiple siphons; highly flow-dependent
2026 status: PROHIBITED at Aachquelle; APPROVED RESEARCH via project access
Early / notable explorers: Tauchclub Singen attempts in 1950s; systematic dives from 1962; Hasenmayer ~300 m in 1967/68 and later to end collapse; Schetter and modern Aach project teams.
KCore note: Hydrological key to the Danube sinking. In 2026 research is still producing new passages and active sump work.
Wimsener Höhle / Friedrichshöhle
Region: Swabian Alb
Location: Hayingen-Wimsen, Baden-Württemberg
Length / development: ~995 m explored
Depth / underwater: to about -60 m
2026 status: RESEARCH ONLY - private property; diving not permitted except approved research
Early / notable explorers: Long research history; modern work by HFGOK and Andreas Kücha among others.
KCore note: Only boat-accessible show cave in Germany; beyond the tourist section lies a deep underwater research cave.
Falkensteiner Höhle
Region: Swabian Alb / Grabenstetten
Location: Grabenstetten, Baden-Württemberg
Length / development: about 5 km class; historic farthest dive reached 26th siphon near 5,000 m
Depth / underwater: siphon depths vary; cave dominated by flood hazard rather than great depth
2026 status: PERMIT / RESTRICTED beyond first constriction; cave diving for experienced research teams
Early / notable explorers: Klaus Böhm first crossed S1 in 1953; Matz/Kolb crossed S2/S3 in 1959; Hasenmayer reached S26 in 1980.
KCore note: A classic German multi-sump expedition cave. Sudden floods are the defining hazard.
Elsachbröller
Region: Swabian Alb / Grabenstetten
Location: Grabenstetten, Baden-Württemberg
Length / development: ~2.204 km
Depth / underwater: multiple difficult siphons; exact maximum depth source-dependent
2026 status: RESEARCH / EXPEDITION
Early / notable explorers: Hasenmayer explored beyond the Schattensiphon in the 1960s; later Arge Grabenstetten teams continue survey and exploration.
KCore note: Likely part of the ancient Grabenstetter Großhöhle; arduous muddy access and multiple siphons.
Büchelbrunner Bröller
Region: Swabian Alb / Grabenstetten
Location: Grabenstetten, Baden-Württemberg
Length / development: ~430 m currently described by Arge page
Depth / underwater: S5 / Trichtersiphon to ~25 m; S4 and S5 ~65 m long each
2026 status: RESEARCH / EXPEDITION
Early / notable explorers: 1960s/70s attempts; pumping 1978/79; Josef Schneider pushed to the present endpoint in 1982/83.
KCore note: Tiny on the map, brutal in practice: almost continuous restrictions and siphons. Current endpoint remains open in principle.
Schlossbergbröller
Region: Swabian Alb / Lenninger Tal
Location: Gutenberg / Lenningen, Baden-Württemberg
Length / development: ~600 m already surveyed by 2022; further exploration ongoing
Depth / underwater: multiple siphons; one unresolved tight siphon at frontier
2026 status: RESEARCH / EXPEDITION
Early / notable explorers: Modern discovery; Andreas Kücha and Jörg Haußmann/HFGOK-associated teams.
KCore note: Young cave with real discovery potential beneath the Schopflocher Moor.
Mordloch
Region: Swabian Alb / Roggental
Location: Böhmenkirch-Steinenkirch, Baden-Württemberg
Length / development: ~4.576 km current survey
Depth / underwater: S2 78 m long / 3.5 m deep; S4 82 m / 7 m; later siphons shallow but extremely tight
2026 status: CONDITIONAL / RESEARCH; flood-sensitive
Early / notable explorers: Manfred Keller crossed S1 in 1959; Hasenmayer and Alexander Wunsch crossed terminal siphons 1964/65; later regional teams.
KCore note: Known for the dramatic 1977 flood entrapment. New survey work shows the cave remains scientifically active.
Wulfbachquellhöhle
Region: Swabian Alb / Upper Danube
Location: Mühlheim an der Donau, Baden-Württemberg
Length / development: major documented source-cave system; dedicated 245-page monograph
Depth / underwater: multiple flooded passages; exact public metrics not consistently published online
2026 status: RESEARCH ONLY / SENSITIVE
Early / notable explorers: HFGOK long-term project; cave-diving research is a central method.
KCore note: Important enough to have a dedicated regional monograph; detailed data are deliberately less public than destination-cave data.
Mühlbachquellhöhle
Region: Franconian Alb / Altmühltal
Location: Dietfurt-Mühlbach, Bavaria
Length / development: 11.096 km surveyed (3/2025)
Depth / underwater: generally shallow sump diving; e.g. OS6 ~9 m, NE 'Menschenfresser' >9 m; siphons up to ~120 m long
2026 status: RESEARCH ONLY - locked access
Early / notable explorers: Karstgruppe Mühlbach; decisive breakthrough 3 Jan 2001 by Dieter Gebelein, Steffen Hoffmann and Manfred Walter.
KCore note: Germany's great modern cave discovery. Eight east-branch siphons lead to a collapse, while dye tracing proves the underground river continues much farther.
Frettermühler Wasserhöhle
Region: Sauerland / Attendorn-Elspe limestone
Location: Finnentrop-Fretter area, North Rhine-Westphalia
Length / development: ~500 m surveyed after new dry access was opened
Depth / underwater: historic water endpoint ~9 m deep
2026 status: RESEARCH / PRIVATE ACCESS
Early / notable explorers: K. Scheller and D. Stoffels discovered source section; first dives early 1980s; later regional teams and new entrance work in 2017/18.
KCore note: One of the few significant Sauerland systems directly entered through a spring; links a water cave to a later dry access.