Every great port city has its secrets. In Ukraine's largest Black Sea city, Odessa, the secrets are buried — literally. Beneath the limestone bluffs and wide boulevards of this famous city lies the largest catacomb network in the world: an estimated 2,500 kilometres of tunnels, passages, rooms, and chambers, most of them uncharted, running between three and 30 metres below street level.
For comparison, the catacombs of Paris — the world's second most famous underground network — span roughly 300 kilometres. Odessa's network is eight times larger.
How Were They Created?
The Odessa catacombs were not originally built for burial or defence. They are the byproduct of over a century of quarrying Pontic limestone — a soft, cream-coloured stone that was the primary building material for Odessa from its founding in the late 18th century. As builders cut stone blocks from below ground in an process called bell-pit or gallery quarrying, they left behind a branching network of corridors that grew with each new construction project above.
By the mid-19th century, Odessa had a population booming fast enough to require constant new construction — and thus constant new quarrying. The tunnels grew organically with no central plan, branching and overlapping beneath the entire city and extending several kilometres into the surrounding countryside. Because the quarrying was done piecemeal by hundreds of different contractors over decades, no complete map of the full network has ever been produced.
Smugglers, Revolutionaries, and WWII Partisans
From almost the moment the tunnels became extensive enough to be useful, Odessa's criminal and political underground found them. Smugglers used them to move contraband from the port without passing through customs. During the revolutionary period of the early 20th century, the passages sheltered political operatives moving through the city under surveillance.
The most historically significant use came during the Second World War. When Romanian and German forces occupied Odessa in October 1941, Soviet partisan units went underground — literally. The Partisan Detachment No. 1 of Odessa used a section of catacombs known as the Nerubayskoye catacombs, about 20 kilometres from the city centre, as an operating base for over two years. A group of partisan fighters lived, planned operations, and launched raids from these tunnels from 1941 to 1944, despite extraordinary efforts by occupying forces to locate and destroy them.
A museum at Nerubayskoye, the Museum of Partisan Glory, preserves much of the original partisan camp essentially in situ — sleeping quarters, communications equipment, a printing press, weapons caches — and remains one of the most emotionally powerful WWII sites in Eastern Europe.
Visiting the Catacombs Today
Access to the Odessa catacombs is strictly controlled — and for good reason. Many sections are dangerous: unstable ceilings, flooded passages, disorienting branching corridors, and no mobile signal underground. Each year, unsanctioned explorers become lost in uncharted sections and require rescue operations that can last days.
The two main legitimate access points for tourists are:
- Museum of Partisan Glory, Nerubayskoye — Guided tours through the partisan camp section, lasting approximately 1–1.5 hours. The most historically significant part of the network and the most visitor-oriented.
- Odessa Catacombs on Mayachna Street — A shorter tourist circuit in a section of the city-centre network. Guides provide context on the geological and social history of the tunnels.
Unofficial catacomb exploration (called digging by local enthusiasts) is deeply embedded in Odessa subculture and has been practiced since the Soviet era, but it carries genuine risks and is undertaken without legal sanction. For visitors, the guided museum experiences provide all the atmosphere and historical depth without the danger.
What to Expect Underground
The tunnels smell of damp chalk and cool stone. Temperature stays between 10–14°C year-round, making a jacket obligatory even in August. Narrow sections require crouching; tall visitors will spend much of certain tours bent at the waist. Lighting in the tourist sections is minimal — bring a torch if you prefer your own light source. The silence, broken only by the guide's voice and the occasional drip of groundwater, creates an atmosphere that no surface attraction in Ukraine quite matches.