Every year, about a million people travel to gorgeous, lively Cracow, then voluntarily disappear down a deep, dark hole in the ground. Not the result of an agoraphobia epidemic, but the lure of one of Poland's most famed attractions - the Wieliczka Salt Mine. Poles hewed rock salt from this mine for 700 years which, as you can imagine, means an awful lot of hollowed out space hundreds of metres under the ground.
As impressive as a centuries old labyrinth extending for 287 kilometres under the Polish countryside may be, that's not why thousand flock here every day. Generations of miners also carved fantastic, baroque sculptures and entire chapels from the softly glowing walls of their subterranean workplace. The result is an underground world with cavernous spaces and winding passages you will not want to take alone - some intricately worked, some roughly hacked.
Visitors to the mine are taken around a 3.5 km route by nattily uniformed guides that takes in an underground lake and the best sculptures and chambers. Access to the mine is via an atmospheric, but long, staircase down to the deep. Getting out entails a brief but terrifyingly rapid accent in a caged miners' elevator.
There are not many places in the world that offer a tour of a defunct socioeconomic system, but Cracow is one of them. The idea of the Communism Tour is to show us soft moderns what life was really like under the totalitarian regime that ruled Poland, and a significant proportion of the rest of the globe, for several decades of the 20th century - it's a lot more fun than it sounds.
The basic idea is that a guy in a coughing, 1970s-vintage Trabant drives you around the Cracow district of Nowa Huta - built as an ideal socialist suburb in the 1950s and 60s. They show you typical apartments from the era, equipped with period furniture and knick-knacks, take you to a socialist-style workers' cafe for lunch, point out remnants of Communist monuments and generally make you feel like you've stumbled into a Cold War thriller. The whole thing is about local colour and amusing/terrifying anecdotes rather than a dry dialectic of history.
Usually overlooked by Cracow's millions of visitors (who voluntarily visits an industrial district on holiday?), Nowa Huta is actually a fascinating part of the city. Based around a steel mill of truly epic scale (which is still in operation), the area was supposed to show the world what central planning could do - instead it became one of the hot beds of opposition to the regime. It's denizens remain proud folk, standing a little apart from the cosy romanticism of the Old Town.
Cracow will never be quite like Europe's other beautiful, ancient cities, because only Cracow sits next to one of the most notorious sites of the Holocaust - the Auschwitz-Birkenau complex. There is something about having such a sobering monument so close that means Cracow will never have the simple, carefree atmosphere of other popular destinations - it lends both a poignancy and a sense of raw, recent history that adds something profound to the atmosphere.
There are many ways to get to Auschwitz from Cracow, a journey of about 75 km, but by far the best and most efficient is with a private Auschwitz Tour. A driver picks you and your party up from right outside your accommodation in the city, takes you to the camp complex, where one of the site's excellent guides will be waiting to show you around, takes you to the nearby Auschwitz II Birkenau site for another tour, then drives you home again. No buses, no waiting, no crowds.
Many people struggle with the question of whether it is right to visit Auschwitz, perhaps worried that a day-trip is somehow making light of the terrible suffering the place saw. The clearest answer to that is to remember that many of those who survived the camps, or saw their loved ones perish there, were determined that the place should be persevered as a memorial, and a reminder, for all to see. Nobody comes away from an Auschwitz Tour unaffected, but very few regret having done it.