Bulgaria's Underworld: Caves, Bats and the Gate Where Orpheus Descended

Every country advertises its mountains and beaches. Almost nobody advertises what's underneath them — which is a shame, because Bulgaria underground is one of the most surprising landscapes in Europe. Karst rock, patient rivers and a few million years have carved out thousands of caves here, and a handful of them are genuinely world-class: caves with eyes, caves with resident bat colonies the size of a small town, and one cave the ancient Greeks believed was the door to the underworld itself.

We've been taking travelers underground for years. These are the ones worth your daylight — organized the way we actually visit them, in two clusters.

The northern cluster: three caves, one unforgettable day

Prohodna — the Eyes of God. From inside this vast rock tunnel near Karlukovo, you look up and two enormous, almost perfectly eye-shaped openings stare back at you from the ceiling — complete with rock "eyebrows." When it rains, the eyes appear to weep. Photographs do not oversell this place; if anything they undersell the scale, because Prohodna is Bulgaria's largest cave passage, and standing under those eyes you feel about the size of an ant with a camera. It is also, for the brave, one of the few places in the world where you can bungee jump inside a cave.

Devetashka. If Prohodna is eerie, Devetashka is majestic — a cathedral-sized chamber with openings in its ceiling that pour columns of light onto a green cave floor where a river runs through. People have lived in this cave, on and off, since the Stone Age. Today its permanent residents are around 30,000 bats, one of the largest colonies in the Balkans, which is why parts of the cave close in early summer while they raise their young. Hollywood noticed too — an action blockbuster was filmed here — but the bats, frankly, remain the better story. Come toward dusk in the right season and you can watch the evening commute.

Saeva Dupka. The connoisseur's cave. Where the first two impress with scale, Saeva Dupka impresses with detail: five halls of stalactites, stalagmites and flowstone formations built drop by drop over tens of thousands of years. The acoustics inside are so good that choirs occasionally perform concerts in the main hall. This is a guided show cave with proper lighting and paths — the easiest walking of the three.

Nearby, and usually combined with Devetashka on our Lovech route, are the Krushuna waterfalls — terraced travertine cascades in a surreal mineral turquoise, like someone relocated a small piece of a tropical island into the Bulgarian forest. After a morning underground, they are the perfect return to the sunlit world.

The Rhodope cluster: the deep south, where myth lives

Devil's Throat. In the Rhodope Mountains near Trigrad, a whole river suddenly vanishes into a mountainside and crashes 42 meters down inside the rock — the highest underground waterfall on the Balkan Peninsula. You enter through a man-made tunnel and stand in a chamber they call the Hall of Thunder, named for exactly what you think. Here is the detail that keeps scientists and romantics equally busy: nothing that falls into this water ever comes out. Divers and researchers have sent tracked objects in; the river surfaces again a few hundred meters away, but the objects simply never reappear.

The ancient Greeks knew this place, and they decided it could only be one thing: the entrance to the underworld. This, legend says, is where Orpheus descended to bring Eurydice back from the dead. Standing in the thunder and the dark, you will not find the idea far-fetched. The exit, fittingly, is a steep staircase of some three hundred steps climbing alongside the waterfall — you leave the underworld the hard way, which feels correct.

Eagle's Eye. Because a day this deep needs balance, we pair the underworld with the opposite extreme: a viewing platform bolted to the cliffs at over 1,500 meters, hanging above the Buynovo gorge near Yagodina. The ride up is an adventure in itself — a proper off-road climb — and the reward is the Rhodopes rolling to the horizon beneath your feet. In one day you stand at the bottom of Bulgaria and on top of it.

Which cluster is for you?

Traveling with kids? The northern cluster is the family favorite — short approaches, manageable walking, and honestly, no child has ever been bored by a giant cave with eyes or a river full of bats. Saeva Dupka's guided path works from roughly age five up.

Chasing drama? Go south. Devil's Throat plus Eagle's Eye is the more physical, more atmospheric day — moderate fitness needed for the stairs and the terrain, repaid with the best story you'll tell when you get home.

Can't choose? They're in different corners of the country, so combining both means two separate day trips — the north runs from Sofia, the Rhodope day from Plovdiv. More than a few of our guests have done exactly that, one from each city.

Practical notes from the guides

Caves hold a steady 10–12°C all year — a jacket in August feels silly in the parking lot and brilliant fifteen minutes later. Wear shoes with grip; cave floors and travertine are slick. Photography is welcome everywhere, but tripods and patience beat phone flashes in the big chambers. And in Devetashka, mind the seasonal closures — the bats were here first, and we like it that way.

Going underground with us

All of these are reachable independently with a car and some planning. But the caves are exactly where a guide earns their keep — the geology, the Stone Age layers, the Orpheus myth told properly in the Hall of Thunder rather than read off a plaque in the parking lot. Small groups, hotel pickup, and all the practical details handled. The tours below cover both clusters — pick your entrance to the underworld.