I stood at the flimsy, makeshift fence that separates Greece from Macedonia, which pens back thousands of refugees making their way to a new life in Europe.

Two Greek border patrol officers allowed them to pass through a small gap, single-file and in small groups; mothers with babies in their arms, young men carrying sheets of cardboard to save them sitting on the cold, hard ground.

No one checked passports, no one was stopped.

The officials, although carrying pistols in their belts, merely kept order and waved them through.

Seeing this with my own eyes, I could understand how, just weeks ago, two of the men behind the Paris terrorist atrocity that was to shake the world had done exactly that, passing only feet from where I stood.

It is likely that when Abdelhamid Abaaoud, 29, the mastermind behind Friday's attacks, and suicide bomber Ahmad al-Mohammad, came this way, the passage was even easier.

In place of the now operational camp were just a few volunteers and a handful of local police, merely handing out water bottles and words of advice. In what could have been a scene from the current series of Homeland, Greece's interior minister has said fingerprints taken from al-Mohammad's remains match those of a man who registered as a refugee using the name Ahmad at the Greek island of Leros in October.

The camp, such as it is, a field full of barn-like tents, medical stations and portable toilets and showers, wasn't completed until six weeks ago.

It now handles up to 10,000 refugees a day, making it one of the largest in the country.

I watched as Chief Rabbi Ephraim Mirvis and a delegation of United Synagogue rabbis spoke to families displaced by conflict and witnessed for themselves the aid effort being carried out by World Jewish Relief.

All had been told to dress down, removing any visible sign that they were Jewish.

In the bus from the port city of Thessaloniki, I had watched with amazement as the rabbis prepared themselves, pulling out baseball caps to cover their kippot.

I wondered how I would have felt if modifying an integral part of my identity was needed to keep me safe or "so that people felt more comfortable".

And I noticed the grace of those asked to do just that. This trip was not about them. As our minibus approached the camp it became clear the advice to travel under the radar had not quite gone to plan.

A visible gathering formed at the entrance and men in plain clothes and sunglasses lurked on the edges of the road, while a marked police patrol car drove by.

There was a moment of uncertainty, as hushed discussions between our party and the men in sunglasses took place.

"No guns," were the only words I heard, before it was agreed the men identified as Greek anti-terror police would keep their distance, as they followed Rabbi Mirvis around the camp.

Refugees arrived and were handed food and water as they were processed. Given a number, they made their way into one of the arrival tents, a place to sit, rest and charge their phones.

There was no Greek official there to check their documentation, no one other than our group and the tireless volunteers to ask them "how they were?" or "where they were going?"

Our guide, Marie Halaka, from WJR's partner, NGO Praksis, said: "Once they arrive on a Greek island they have to go to a reception service to be registered. Most Syrians have passports but a lot of people from other countries do not. They provide their fingerprints on an electronic device and they are sent over to security that checks they are okay. Then they get a paper so that they can make their onward journey.

"They are not checked again until they are in Macedonia where they will go to another reception centre.

"This border crossing is illegal. That is why they are not checked here. The point of their being refugees is they have to travel illegally."

She explained nearby there was a normal border where if I wanted to cross, people would check my passport and ask me why I was coming in.

Our own security kept their distance, and at one stage even blended into the crowd, only to be identified, when Rabbi Mirvis asked them if they were "from Afghanistan?".

A tall man in T-shirt and jeans replied: "No, Greek."

It was not hard to see how easy it could have been for someone to hide themselves among the hundreds of people fleeing conflict.

Since Paris, Rabbi Mirvis has warned that closing borders to refugees in response would not make sense.

He said he was concerned about a backlash against "the victims of evil, not the perpetrators".

And he was right. The people who I saw, the children that I played with, were victims, people who had seen their families murdered. Teenagers not allowed an education by the dictatorships that ruled them. The absence of checks and the opportunity for safe passage was not their fault.

We arrived back in Athens in the middle of a national strike - another example that the country the refugees were passing through was, itself, in turmoil.

I got in a taxi with rabbis Danny Bergson and David Mason, keen to reflect on our day at the camp.

But that wasn't possible. Our driver seemed in a rush, agitated as our group of nine discussed who was going to go with whom. He shoved our bags off his seat and pulled away.

"What the f*** is that?" he said, pointing to Rabbi Bergson's kippah.

My heart began to beat faster for the first time that day, instinct telling me these were not the questions of innocent intrigue.

He sped along the highway swinging in and out of traffic erratically.

"It's a kippah," Rabbi Bergson, explained.

"Why do you f***ing wear this?" the driver asked, sounding even angrier.

Stunned into silence, a slow sense of fear crept in. But it was the calm dignity of my fellow passengers that really took my breath away.

We even thanked him politely as he jerked the car into the hotel drive.

Eventually he gave up, but not without reminding me that, in austerity-ravaged Greece, where neo-Nazi party Golden Dawn is on the rise, it has its own problems when it comes to attitudes towards those who are "other".