These days a trip to Auschwitz is not so much a pilgrimage as an essential part of any tourist itinerary.

Travel companies offer the visit as part of a day-trip from Krakow, followed by a visit to the Wieliczka Salt Mine. Advertisers are cashing in on the record numbers of visitors, erecting hoardings on the approach to it. Meanwhile, the boundaries of the local town, Oswiecim, creep ever nearer.

It is a positive thing that about 1.5 million people visited the former death camp last year. But as the number of Auschwitz survivors dwindles, questions are being raised about how to preserve its dignity.

The camp is treated as a cemetery to commemorate the deaths of over a million people.

Many of the exhibits at the Auschwitz museum have been created by survivors and for decades after the war, the museum's director was a former camp inmate, Kazimierz Smolen, a Polish Catholic resistance fighter. His influence continues to be felt and the place is allowed to speak for itself. There is no entrance fee and no modern technology used to create interactive exhibits or recreate scenes. Instead, detailed, informative notices explain the facts and the impact is enormous.

Teenagers posed for selfies at the camp, kissing and pulling faces

But do Auschwitz's millions of visitors feel the solemnity of the place or does time also take its toll? Last year, there was outrage when a series of social media posts showed Israeli teenagers posing for selfies at the camp, kissing or pulling faces and generally appearing to be having a good time.

Meanwhile, in an effort to preserve its authenticity, the museum has no CCTV system to protect it, and exhibits have been stolen or defaced with graffiti.

Other camps in Poland suffer from the same problems. Last year I visited Majdanek, on the outskirts of the city of Lublin, overlooked by incongruous modern apartment blocks. A main road runs straight past the camp, with the barbed wire, guard towers and reconstructed chimney of the crematorium in plain view from passing cars.

Women pushing buggies stroll through the parkland outside. Polish families from Lublin city centre use Majdanek as a place to visit at weekends for a break from the city.

Inside, however, there is a sense of reverence. Guides speak in hushed voices and tour groups trudge silently across the huge site. A recent class of Israeli high school students were clearly awed by the camp, singing, praying, a few of them openly crying.

And yet, it is hard to get away from the fact that Poland is a country with a Jewish history but very little Jewish life. The museums and restored ghettos are run by non-Jewish Poles determined to honour the memory of those who were killed by the Nazis - but as the years go by and the survivors die, the link becomes more tenuous.