Luton airport. O5OO hours, 181 A Level students from 77 schools, tossing their hair, discussing makeup, trainers and the merits of olives. Their mobile phones are a constant. A low ebb of white adolescent noise.

Seven hours later, there was only utter silence, but even the birds don't sing at Auschwitz so it’s little surprise the stunned teens found it hard to articulate what they saw or felt.

We are here courtesy of the Holocaust Educational Trust, a government funded body set up to remember the Holocaust and educate oncoming generations about its existence and consequences.

Nowhere can do that quite like Auschwitz.

It was here in Poland that 1.1 million predominantly Jews but also gypsies, intellectuals, homosexuals, prisoners-of-war and criminals were captured, herded and systematically murdered here between 1941-45 by the Nazis from all over Europe, on an unprecedented scale, while around them WW2 waged.

The brutality, cruelty and absolute disregard for human dignity were evident from the moment we walked through Auschwitz’s ironic wrought iron gates proclaiming Work Will Set You Free, into the horrors beyond. “I just call it hell” Rabbi Andrew Shaw told me quietly.

And if there is a vision of hell this must be it; with its human ovens manned by inmates, it’s firing squad alley where thousands were shot, its roaring crematoriums and the endless rumble of trains brining the next load of hapless victims to meet their fate on these cold, bleak Polish killing fields, all in plain view of the commandants house whose children played happily in the gardens.

The gallows, the torture racks, the rooms full of hair, shaved off all women and girls on arrival and then sold to the German textile industry, braids still intact, the suitcases, hastily daubed with paint, family names still in evidence, the last vestiges of hope, colourful pots and pans, prayer rugs, none of which would be needed where they were going, later redistributed to the German population.

But it was the wall of photos which finally broke me. In 1942 each prisoner was photographed, shaven-headed and dressed in the obligatory 'striped pyjama' uniform, their expressions varying from defiance to fear, hope to despair, insolance to disbelief, the dates of their arrival and their imminent deaths carefully recorded.

Here were young men of just 17, the same age as my children, still uncertain of their fate, of the wave of evil about to enclose them, and I crumbled.

Visitors shuffled from room to room unable to meet each other’s eyes, as if we were complicit by simply being human beings, a shameful recognition that as a race we were somehow capable of this.

Auschwitz was just the beginning, the ice breaker, because the second camp Birkenau, part of Auschwitz but separate, was the big Daddy of the genocide world, 20 times larger, purpose built, and a much more efficient killing machine.

80% of the death train inhabitants were killed on the side of the tracks on arrival in gas chambers masquerading as showers. Those picked for the work camps lasted on average three months, worked and starved to death almost as quickly, or perishing in the experimental chambers of the notorious Josef Mengele, otherwise known as the Angel of Death in his medical block.

Led around by our guide Polish Marta Kadtucska, who was just the right side of angry, she showed us the remnants of the 330 accommodation huts, some still standing, the ruined red brick chimneys stretching away into the distance, burnt to the ground by in 1945 as they retreated from the Russians, desperate to hide the evidence of their war crimes and mass extermination programme.

And it is this, which wedges itself at the back of my throat. The passionless, zealous, ruthless, remorseless of the Nazi’s campaign to "free the German nation of Poles, Russians, gypsies and Jews" using the resulting ashes as fertiliser on the nearby fields,

By the time we reached Birkenau we were numb, silent, tired, emotional, exhausted, unable to compute any more horror, saturated with pain, terror and knowledge, broken in, dispassionate, more of the same on a bigger scale, its inmates treated like animals on a scale impossible to comprehend, even when there on this blood soaked, ash filled landscape.

Six million people were killed in Nazi Germany’s concentration camps, stopped only by the allies actually reaching the camps themselves. In their dying throws, the Nazis speeded up their Final Solution, their ovens and gas chambers raging day and night, the trains rolling into the camps at all hours full to capacity.

Yet it wasn't the horror that shocked the students the most, it was the complicity. "How did it happen? How did anyone let this happen? Why didn’t anyone do anything to stop it?" they asked time and time again incredulously.

But in these days of increasing religious intolerance, war, displacement, bigotry dressed up as patriotism, refugees, camps and the growth of global facism, the hows and whys seemed more relevant than ever before.

But perhaps our accompanying rabbi Andrew Shaw said it best: “How should we feel in this place of loss and persecution? I feel a sense of pride because the Jewish people will go on, as will their values and practices. They destroyed our bodies not our souls.”

And as we lit candles to remember the dead, the next generation absorbing and processing what they’d seen, resolving never to let this happen again in their lifetimes, there was a sense of hope in the air amongst the devastation of those left behind. And for that at least we must be grateful.

Overview of the camp’s history

Auschwitz concentration camp was established by the Nazis in 1940 at a former army barracks in O?wi?cim (Auschwitz in German), a town in German-occupied Poland.

The camp was initially established to intern the increasing numbers of Polish political prisoners arrested by the Nazis after the German invasion of Poland in 1939.

Auschwitz was significantly expanded in 1941, with the creation of new camps (notably Birkenau), which were initially designed to hold Soviet prisoners of war. All civilians living near the camps were evicted, with approximately 1,000 homes destroyed and others requisitioned for Nazi use.

In early 1942, Auschwitz was assigned a role in the emerging Holocaust. Although most Polish Jews were murdered in other extermination camps such as Treblinka, Be??ec and Sobibór, Auschwitz’s position at the heart of the European rail network meant that it increasingly became the principal destination for deportations of Jews from elsewhere in the continent.

The peak period in Auschwitz’s history was the spring of 1944, when more than 400,000 Hungarian Jews were deported there following the German invasion of Hungary in March 1944.

At the end of 1944, with the Red Army approaching, the Auschwitz administration began to remove traces of the crimes committed there by destroying documentation and buildings (as a result some of the buildings at Auschwitz-Birkenau today were reconstructed using original material or result from conservation efforts by the Auschwitz-Birkenau State Museum).

Between August 1944 and January 1945, 120,000 prisoners were evacuated to camps in Germany, usually on cattle trucks or in brutal forced marches known as ‘death marches’. Most of these evacuations took place in the middle of winter. Many of the prisoners died due to the freezing conditions, hunger and shooting by the guards.

The remaining 7,000 or so prisoners were liberated by the Red Army on 27th January 1945.

The Auschwitz-Birkenau camp system

Whilst today the whole complex is referred to as Auschwitz-Birkenau, the name actually refers to three separate main camps with different purposes, as well as dozens of sub-camps.

Auschwitz, also referred to as Auschwitz I, was primarily a concentration camp which held around 15,000 prisoners, although this figure sometimes rose to more than 20,000. This camp was initially used for Polish political prisoners. It later also housed Soviet prisoners of war, ‘anti-social elements’ and prisoners of many nationalities. Harsh working and living conditions led to high death rates.

Birkenau, also known as Auschwitz II, was the main extermination camp. It was built in 1941 on the site of the village of Brzezinka, 3 km from O?wi?cim. It was originally intended that Birkenau would be a slave labour camp for Soviet prisoners of war. However, from 1942 it became a killing centre for Jews, being the site of the main gas chambers and crematoria. At the same time, Birkenau also remained a slave labour camp: the minority of Jews who were not selected for immediate death in the gas chambers were put to work, with the intention that they would be worked to death. In 1944, this area held over 90,000 prisoners.

Monowitz, or Auschwitz III, developed around the Buna chemical factory, one of many factories which were founded around Auschwitz-Birkenau. This was primarily a slave labour camp; many of its inmates were Jews.

Victims of Auschwitz-Birkenau

As most Jewish victims were murdered upon arrival and therefore never entered in the camp’s records, it is impossible to give precise figures for the numbers of people sent to Auschwitz. However, the Auschwitz-Birkenau State Museum estimates that the number of people deported to Auschwitz included: 1.1 million Jews; 140,000 Poles; 23,000 Sinti and Roma (‘Gypsies’); 15,000 Soviet prisoners of war; 25,000 victims from other groups. From these around 1.3 million deportees, around 1.1 million were murdered.

Most Jewish prisoners were murdered in gas chambers. The gas chambers used a pesticide called Zyklon B: pellets, which became active on contact with air, were emptied through a hatch by an SS man.

One gas chamber was created at Auschwitz I in late 1941 but in 1942 killing operations largely moved to Birkenau where two gas chambers were created in specially adapted cottages near the camp. These were replaced in 1943 by four large purpose-built buildings which each included gas chambers and crematoria.

The gas chambers were also used to kill Roma prisoners in 1944 as well as prisoners who were no longer able to work.

Other prisoners died from disease, starvation, exhaustion or brutal treatment by guards.

The overall number of people murdered at Auschwitz-Birkenau in the years 1940-1945 is estimated to be approximately 1.1 million people.