The time is Monday afternoon. We’ve just landed at Kraków airport, Poland. We have a five hour layover on our journey from Amman (Jordan) to London (England). The sun is shining. What could we possibly do with that time? Read a book? Play cards? Stare at our phones? Return the bored stare of fellow travellers?

This is what we did. A quick internet search for ‘wild swimming Kraków’ brings up a former quarry called Zakrzówek. The quarry is a 20 minute cab ride away. Apparently, ‘This fantastic reservoir was serendipitously created when the limestone quarry operating here accidentally pierced the water table.’ Pope John Paul II worked there during the German occupation of Poland. We withdraw some Polish Zlot from the cash machine and book an Uber. Ordering an Uber in Poland makes us feel a bit nervous but adds to the excitement of wild swimming in a country neither of us has visited before.

Our cab driver clearly thinks he has picked up some eccentrics. “But the water will be cold,” he exclaims, in very good English. “I can take you to a warm swimming pool?” We politely decline and gaze curiously out of the taxi window as we pass pretty Polish houses and huge billboards announcing a forthcoming Rod Stewart gig. Eventually, at the end of a long quiet track we spy the reservoir. Our cabbie pulls up next to an unscalable metal fence. Doubts begin to palpitate in our minds. Did we overlook something in our excitement? We could be polishing off doughnuts and drinking coffee in the airport. Our driver looks over his shoulder at us with a sceptical gaze. “What about Brexit?” he shrugs, obviously hoping for some more chat and a fare back to the airport. That settles it.

After a bit of scouting around, we find ourselves standing in front of a tall, locked iron gate. Behind the gate, we observe a narrow path leading tantalisingly down to the water’s edge. We haven’t come this far to about-face, to look back and remember the time we nearly went swimming in Poland. That’s not how the story goes. What’s ‘Open Sesame’ in Polish? Beside the gate, we find an old push-button doorbell. John courageously steps forward, pushes the button and immediately stands behind me, dread in one eye, mischief in the other. Tiredly, the rusty electric gate trundles open. Like Dorothy entering the Emerald City, we step forward.

The Zakrzówek quarry is home to the Kraken Diving Centre. They have a clubhouse at the lake where we stop and explain to a laid back young man that we’re in Poland for a few hours and just want a quick swim. ‘OK, but just for 10 minutes,’ We take that to mean ‘stay as long as you want and enjoy the sunset’.

Eagerly getting changed at the water’s edge, we finally get the opportunity to take in the beauty and vastness of the lake. Trees are layered in the light green of new life atop white cliffs towering magnificently over the water which shimmers in the late afternoon sunshine. Meanwhile, serious looking divers in thick neoprene suits lumber past us like spacemen, carrying metal oxygen tanks towards Planet Zakrzówek. They disappear into the depths without stopping to acknowledge our existence.

The water is clear and inviting. As per, I’m in first, stepping cautiously, then launching myself out into the fathomless water, a little nervous of the hidden depths, 20 metres deep in some places. The coldness assaults my senses with its crisp sharpness. I quickly relax and smile as my skin begins to tingle. A wide golden path shimmers across the water to the rocky heights. My head up, taking in the vista, I breaststroke around the water’s edge until my fingers and toes start to numb. I climb out, but can’t resist a couple of cheeky running jumps back in to complete the experience. John is much more audacious, diving straight in from a three metre high jetty. He’s watched by small groups of inquisitive locals scattered around the cliff tops. Quickly he climbs the metal ladder to fly out again, gasping and laughing, cheered on by the natives. Release The Kraken.

Sated and shivering, we dress quickly and drag our cases to the cliff tops where local youth gather in groups smoking and chatting. Happily we gaze over the darkening water, eating rollmop herrings and pickles

John Weller and Lola Culsán are authors of the best-selling travel book, Wild Swimming Spain