Two Kilometres of Three

Day nineteen, Bosnia. „We've cleared two kilometres of three,“ says Esmar Alimanovic, who is taking us through the tunnels at Ravne.

The authorities won't allow further digging on the Pyramid of the Sun, so in 2006 Dr Osmanagić went looking for another way in. „There are around seventy thousand pyramids in the world,“ Esmar says. „Most of them have tunnels underneath.“ They found an entrance at Ravne and started clearing it out with shovels and wheelbarrows, which is as slow as it sounds. The ten euros for the tour pays for the digging.

„Five thousand years ago the tunnels were sealed. By whom, we don't know.“

He talks about the air down here, which he says is full of negative ions and good for you. I have been in mine workings and cave systems in Germany and in Italy, and the air in them can sit in your chest like old cloth. Down here my lungs go deeper without being asked. Make of that what you like; I only report it.

Dry stone walls. Boulders. Wooden beams. Wall surfaces that don't look like anything I know.

Some of the visitors have come to meditate. Nobody is embarrassed about it, which is its own kind of achievement.