Ours was the twentieth coach in the vast car park outside the camp. There was a bright cafe and birds singing in the trees. It looked like any other touristed historic site - except for the parallel lines of train track.
Our guide instructed us not to stray as she led us to the front gate. A pattern was being set for the tour. We moved in tight little tourist groups in and out of buildings as the voices of half a dozen guides competed in as many languages.
Cameras clicked furiously. The walls around us were obscured by huge signs. It took a while to realise that our guide never deviated from the information on the signs and the other vast posters around the museum.
The fate of the Jews - the true horror of Auschwitz - was minimised, sandwiched in somewhere between stories of Polish political prisoners and other local inmates; we were not even shown the Jewish section of the museum.
Our guide was unemotional, and she did not tolerate emotion in us. When a stray tear slipped onto a cheek, she moved us on. Her steely calm turned the tour into a practical guide on the operational and logistical problems of exterminating immense numbers of people. It became clear that the camp commandant's biggest problem, apart from disposing of bodies, was coping with the personal possessions that his victims brought with them.
In room after room, those possessions - clothes, shoes, toothbrushes, spectacles, even hair - were stacked high behind vast, glass windows. Almost everything was covered with a grey dust. Only the suitcases, piled crazily to the roof of one room, seemed connected to real people.
Outside Block 11, the Death House, votive candles and bunches of flowers brightened the "death wall" against which thousands were shot. But everything was sanitised. Even the bricks in the walls were clean. The "hunger cell", where prisoners were starved to death, was filled with flowers.
We paused at the gallows where Rudolf Hoess, the camp commandant, was hanged two years after the war ended. Our guide rushed us through the first experimental gas chamber into the crematorium, where the furnace doors stood open revealing a wreath laid by British Fusiliers, "lest we forget".
When the doors slammed behind us, shutting us into the darkness of a cinema, there was an audible mass intake of breath. It was a relief when, after 20 minutes of flickering images of emaciated prisoners, the doors opened and we were given a break for lunch.
But only 10 minutes later, it was on to Birkenau for more closely supervised tourism. The guide said her piece and swept us on. We were discouraged from seeing anything else.
We were not told of the remains of a crematorium at the end of the track. We did not see the pond silted with human ash. Instead, we climbed the observation tower and gawped, like the tourists we were, at the panoramic view of the camp.
German and Polish schoolboys around us laughed and cheered. They pushed us in their eagerness to see, arguing, chewing gum and taking photographs as their teachers tried to teach them their history.
We descended the stairs to be told that we were to board the bus "now". My friend was in the book shop. "We'll join you in a minute," I said. The bus escort smiled. "You don't understand. We are boarding the bus now."
"We will buy our books and join you." "Now!" he said. "Now!"
It was deeply unpleasant to feel that here - of all places - we were being so thoroughly, so needlessly, controlled.