“Are you ready?” asks Christopher, a guide from the nearby village of Wieliczka. He’s cloaked in a long charcoal jacket and blowing on his hands to keep warm. For a giant-sized man, he uses a soft voice. “Because once we start, I will not be able to talk to you. And you will not be able to turn back.”

It’s an ominous message, but we are about to climb 100 meters beneath the earth.

“Kopalnia Soli,” say the black letters ahead of me, pressed into a plate of gold, a haze from my breath forming a cloud over the pick-axes.

Koplania Soli – The Wieliczka Salt Mines

“Eight hundred steps,” Christopher says again as a final warning. Automated instructions blast in English, German and Polish, an official steps aside and we begin the descent, down, down, down into Kopalnia Soli: Wieliczka’s salt mines and a World Heritage Site to boot.

Work began here back in the 13^th century and the mines have been functional ever since, through landslides, floods, the Nazi invasion and communist Russia. The real story, however, started 20 million years ago, when the sea covered this part of Poland, leaving behind buried treasure in the form of sodium chloride.

There’s plenty of time to contemplate history, geology and chemistry as the creaking wooden staircase goes on and on, round and around, down and down. Over a million people visit each year and it’s difficult to see how this contraption copes. We traipse through makeshift corridors, stooped in the bare light of a few electric bulbs. So far, Wieliczka is living up to the promises made by all mines: dark, dirty and dangerous.

So far, Wieliczka is living up to the promises made by all mines: dark, dirty and dangerous.

St Anthony’s Chapel changes all that. Carved by the miners into the leaden rock salt, this fairytale world of life-size statues glistens under the quiet, soft light.

Like all good fairytales, there’s a princess involved. According to legend, when Princess Kinga of Hungary became betrothed to King Boleslaw the Bashful around 700 years ago, she threw her engagement ring into Hungary’s salt mines. This, somehow, was supposed to guide her to the salt supplies in her adopted country, Poland. When drilling started in Wieliczka, miners found not only salt but the engagement ring itself.

Our next royal encounter is a little more sedate: a traditional bust of King Kazimierz the Great, Krakow’s most famous ruler, whose name still describes the city’s revived Jewish Quarter. Next up was the great scientist, Copernicus, the first man to stare into the heavens and calculate that the Earth was not actually the centre of the universe after all.

Standing in his footsteps so deep beneath the earth (Copernicus came to Wieliczka as a student in the 15^th century), it’s a struggle to remember that the stars even exist, let alone worry about which direction they’re spinning in.

Down here, salt instead of stars decorate the ceiling. And although raw rock salt looks a mottled granite gray, when water seeps in the crystals dissolve to reappear in brilliant, tangled, fragile formations.

“We call them spaghetti and cauliflowers,” says Christopher, catching my eye. “For obvious reasons.”

I reach out and touch a “cauliflower,” a coarse resilience grazing my fingertips.

The salt crystals are like Wieliczka itself: deceptively beautiful, incredibly tough.

In the museum section, plastic men with hooded faces labour alongside horses, axes and carts. These everyday workers, toiling out of sight of the world, conceived sculptures so impressive that the rest of the world still falls through the earth to see them, some earning a statue of themselves in return. Copernicus, Goethe, local lad Pope John-Paul II. Even a merry dwarf who promises instant fertility if you kiss him on the nose.

The salt crystals are like Wieliczka itself: deceptively beautiful, incredibly tough.

Yet all of these works fade into the shadows at the grand finale: the Chapel of St Kinga.

Salt-diamond light fills this vast 23 000 cubic metre cavern, with each chandelier teardrop consisting of purified, clear salt. Religious panoramas cover the walls and illuminated rose salt, sourced from a neighboring mine, glows as the heart of Jesus and then characterises God himself.

The tour ends with a heart-choking ride to the surface in a caged rocket of a lift but before I leave, I catch a glimpse of Wieliczka’s forgotten heroes. Lamps in place, pick-axes slung over their shoulders, two miners smile at each other, forever frozen in salt.

They seem to be sharing a joke. And perhaps that’s the last of Wieliczka’s great secrets.

Have you ever visited a mine that surprised you?