The first thing you see when you arrive at the Moria refugee camp is a huge metal gate topped with barbed wire. A sign pinned to the front states that no photography or video is allowed.

RTÉ News was eventually granted permission to enter the camp, but when we arrived it was a very different story. We handed over our papers to a puzzled looking security guard. Three police officers approached us, took a quick look at the papers and said: "Not allowed in."

A senior female police officer called Maria was summoned. But a firm shake of the head indicated we would not be getting past the front gate.

We left our phone numbers and walked away dejected, certain we would never hear back from Maria and her police squad. Two hours later we got a surprise call. "Come right away, you have permission," Maria told my fixer Mostafa.

We weren’t given a reason for the sudden change of heart but our tour of the Moria camp was back on.

Two Greek government representatives met us at the entrance and explained the rules. We had 45 minutes to look around the camp and we had to ask permission before interviewing any residents.

They come from Afghanistan, Iraq, Iran, Syria, Ethiopia and Eritrea and many more countries in search of a better life. But once they arrive, it's a very different story. They are faced with squalid conditions and severe overcrowding - 5,000 people crammed into a space designed for around just 3,000.

Migrants at Moria queue in cramped conditions for food

As we climbed the hill near the entrance and turned the corner we saw the sobering reality of living in an oversubscribed camp. Dejected faces stared blankly in every direction and chaos lurked on every corner. Children wandered, sometimes on their own, with little to do.

"Moria bad," shouted one resident. "Moria problem," said another young boy who looked about 12 years old.

Since late last year overcrowding has eased slightly at the EU-sponsored camp. But around 15,000 men, women and children are still stranded on the Greek islands closest to Turkey.

The slow asylum application process means many are marooned here for years living in tents without hot water and electricity. Under a deal struck between the EU and Turkey in 2016 they are unable to leave the island camps and travel to the mainland.

"Everyone is expected to patiently wait their turn. If you step out of line the consequences can be fatal."

We walked over to a long line where hundreds of men where being held in separate pens that resembled a livestock mart.

"What’s happening here?", I asked our Greek guide Spyropovlov Kryiaki.

"They’re queuing for food, its lunchtime," she replied.

"For how long?", I asked.

"Two or three hours," she said as we moved closer to inspect how the system operates.

As we moved forward, a surge of people moved with us, shouting and cheering as the RTÉ News cameraman began filming.

Camp officials told us this is one of Moria’s major hot spots where fights regularly break out as the men grow weary and frustrated waiting hours at a time to get fed.

Everyone is expected to patiently wait their turn. If you step out of line the consequences can be fatal. There have been several stabbings at the food queue and some have resulted in death.

Squalid conditions inside the Moria camp 

The atmosphere is tense until dozens of men are released and allowed up to a small hatch where a packet is dished out along with some flatbread.

"What do you have there?" I ask 18-year-old Afghan migrant Sraheen.

He opens a plastic bag and shows me a small tray with chicken and rice. He spent three hours queuing for this meagre portion and the look of disappointment on his face says it all.

Earlier, he spent just as long queuing for breakfast. When it was his turn to get fed Sraheen said he was told: "There’s no food left. All of the people are hungry today."

I ask him what are the facilities like. "Very difficult. We can't get showers. Life is so difficult, [there are] so many problems."

"Oxfam says many women wear nappies at night because they're afraid to leave their tents to go to the toilet."

The clock is ticking and our Greek guides encourages us to move along. There is no time to probe any further about the conditions.

As I leave the chaos of the food lines behind I ask guide Spyropovlov Kyriaki why there are so few women around the camp.

"I believe they are in the tents because they have a lot of obligations to cook and clean the room," she tells me.

"Maybe they are afraid of going out or they are not allowed," Ms Kyriaki adds.

Women and children are among the most vulnerable migrants living in the Moria camp. Oxfam says many women wear nappies at night because they're afraid to leave their tents to go to the toilet.

Most of the men I met in Moria treated women with kindness and respect. However, officials say there is a minority who sometimes threaten and intimidate single females who are too afraid to walk alone unaccompanied.

Those men who do misbehave are dealt with swiftly. They are sent to an on-site prison where they are held depending on the severity of their crime.

Bins overflow with waste at the Moria camp

Everywhere we went we were approached by migrants desperate to tell us about the intolerable conditions. But we weren't able to speak to everyone.

A tall Jordanian man dressed in a distinctive headscarf approached us as our visit came to an end. He began shouting in Arabic to my fixer Mostafa Almonajid, a former Syrian refugee who arrived on Lesbos three years ago. The man grew increasingly angry as he demanded a chance to tell his story.

I ask Mostafa to explain that we only have five minutes left. ''We have no time'' pleads Greek guide Ms Kyriaki as we start to move away.

The man wasn't happy and followed us until we had made our way back to the main gate. When we got outside he pulled me aside.

He wanted to tell me that if he and his friends knew how bad life was in Moria they would have never have left Afghanistan, Syria and Jordan. ‘’Please tell people how bad everything is. It's hell on earth’’

He then turned,walked back in through the gate and made his way up the hill towards the food centre.

Like most people here, he will spend the rest of the day waiting in line for food, toilets and the showers.

Our tour of Moria is over but for the majority of people inside Moria the long wait to get off the island continues.

With contributions by RTÉ News cameraman Stuart Halligan, filmmaker Fionn MacArthur and fixer Mostafa Almonajid.