Abandoned mines: a safety-first guide
Updated October 3, 2026
An old mine attracts with its history, its galleries and its silence. It also kills, every year, visitors who thought it safe. This guide does not say how to get access: it explains why access is often forbidden, what the real risks are, what the law expects of you, and what a map with a way back to the entrance can add, without ever replacing training.
First, the framework: permission
An abandoned mine is not ownerless ground: it belongs to someone, or falls to an authority responsible for making it safe, and access is very often forbidden for good reasons. Going in without permission can make you and those with you liable. If access is forbidden or closed, do not go in, and do not try to get round the closure.
Legitimate ways to discover a mine exist: guided visits to mining museums and heritage sites, outings run by associations, mines developed for the public. In the United States, the “Stay Out – Stay Alive” campaign from MSHA, the federal mine safety agency, reminds people not to enter abandoned mines. In France, the Géorisques database lists known underground cavities.
The dangers, one by one
None of these risks can be seen from the entrance, and several are invisible even inside:
- Bad air: lack of oxygen, carbon dioxide (the old miners’ “blackdamp”), carbon monoxide, sometimes methane or radon. You can lose consciousness without having noticed anything.
- Collapse: rotten timbers, cracked roofs, unstable fill. A sound, or dust hanging in the air, are warning signs.
- Shafts and voids: a vertical shaft can be hidden by vegetation, planks or a flimsy slab.
- Water: flooded galleries, levels that rise after rain, cold that wears you out.
- Leftovers: old explosives or chemicals, corroded ladders and stairs.
- Protected wildlife: bats hibernate in many mines, and disturbing them can be fatal for them. In several countries, it is prohibited.
- Isolation: no network, so no call possible from underground.
Never alone, never without telling anyone
The basic rule is the same as in caving: you do not go down alone, and you do not leave without giving someone you trust the exact place, your planned return time and the time at which they should raise the alarm. In a group, progress follows the slowest, and anyone who feels unwell (headache, dizziness, sudden breathlessness) signals the turn back immediately.
A properly calibrated multi-gas detector is a professional’s tool, which does not guarantee safety and does not replace experience. A scanning app detects no gas at all.
Preparing for an authorised visit
Even with permission, a mine is not approached on a whim:
- Get trained: an introduction to underground progression, through a club or a federation (in France, the Fédération française de spéléologie), teaches lighting, cold, rescue and team progression.
- Get informed: ask the owner or manager about the state of the site, closed areas, rules and emergency contacts; look at old plans and the weather.
- Get accompanied: a guide or someone who knows the mine is worth any equipment.
- Set limits: a turn-back time, a maximum depth, a stopping criterion (feeling unwell, the sound of rock, rising water).
Planning for rescue
In a mine, mobile coverage disappears within the first metres. Before any authorised visit, know the emergency number (112 in Europe, 911 in the United States) and be able to give your exact position: town, name of the site, entrance used. In France, underground rescue is mobilised through 112 or 18, which alert the specialised teams.
If someone is injured or lost, stay together, save light and wait for rescuers: splitting up doubles the problem. Minimal equipment includes a helmet, three independent light sources, good boots, gloves, water, a survival blanket, a first-aid kit and a whistle.
What a map and a way back to the entrance can add
On a site where you are entitled to be, Lidark keeps track of your path offline: a live minimap, the real return distance along the path walked, landmarks dropped for junctions and dangers, and red night vision. It is an aid against disorientation, not against the other risks.
Let us be clear: Lidark replaces neither a guide, nor a rope, nor a prior reconnaissance. It does not detect bad air, does not judge the strength of a roof and does not alert rescuers. Its range is about 5 metres, and a survey is indicative. Training, supervision and permission remain the foundation. See also finding your way without GPS and the guide to underground quarries.
Documenting without damage
If an authorised visit lets you survey the gallery, a dated 3D model is a good way to keep the memory of a place without degrading it: drop the file into our free 3D viewer to reread it later. Take nothing, damage nothing and follow the owner’s rules. All the guides are gathered on the guides page.
Frequently asked questions
Is it legal to explore an abandoned mine?
It depends on the country and the owner, but access is very often forbidden. Enter only a site where you have permission, or on an organised visit.
What is the main danger of an abandoned mine?
Several risks are deadly: air short of oxygen or loaded with gas, collapse and hidden shafts. They are not always visible.
Can I go alone to take photos?
No. Going alone into a mine, even an authorised one, is the situation where an incident becomes fatal: nobody knows you need help.
Does a phone get signal in a mine?
Generally not, from the first metres. Tell someone your location and your return time before leaving.
Does Lidark detect gas or collapse risk?
No. Lidark helps you find your way and return to the entrance, offline. It measures neither the air nor the stability of the rock.