The social home of caving
A map and a cave page can't give you beta, mentorship, or a trip to actually go on. Grottos can. Each real-world caving club gets its own private, moderated space — and you can belong to as many as you cave with.
✓ Verified grotto
Everything a grotto needs
A private feed
Ask questions, post photos, share current conditions and gate status, like and reply — beta you won't find anywhere online.
Trip-planning events
Post a trip with a meet spot, date and details. Members coordinate and show up ready.
Photos & people
A shared photo gallery and a searchable member directory with avatars and roles.
Trust-based access
Request to join; a moderator approves you. Caving is risky and access is earned — groups vet members the way real grottos do.
Verified before they're trusted
Anyone can submit a grotto, but a site admin verifies it before it appears publicly or unlocks member-only cave locations. Verified grottos wear a ✓ Verified badge. Only members of a verified grotto can see grotto-gated cave entrances.
✓ VerifiedPending verification
Your caves stay protected
Cave locations are the most sensitive thing a grotto holds. Karst is built so the app can't leak them — not by policy, by design.
Locations are fuzzed
Sensitive caves store only a coarse ~3-mile circle — the true point is snapped to a grid before it's ever written. There is no exact coordinate to leak.
Entrances are member-gated
A precise entrance is shared only with approved members of a verified grotto, kept in a separate gated record — never in the world-readable cave data.
Photo GPS is stripped
Every uploaded photo is re-encoded to remove all metadata — including GPS/EXIF — so a location can never ride along in an image.
Bring your grotto onto Karst
Start a general group in seconds, or submit your grotto for verification.