It is extremely rare for Western journalists to be allowed inside the Democratic People's Republic of Korea - home to 25 million people effectively isolated from the rest of the world.

So, for ITV’s On Assignment to be given permission to film inside Munsu Waterpark in Pyongyang was a great achievement.

It took us three days of earning our government minder’s trust. He then relayed accounts of our conduct to his superiors who made the final decision.

These officials were, incidentally, staying in the same hotel as us for the duration of our trip to DPRK. It was so they could control the movements of the international media they had invited there. A hotel that effectively sits on its own island, in the middle of a river.

The world’s broadcasters - and there were three bus-loads of us, because let’s face it, if any press is given the chance to go to North Korea then they jump at it - were invited to the hermit kingdom for a maximum of 8 days in October.

It was to report on the 70th Anniversary of the Founding of the Nation’s Worker’s Party. This was celebrated with a huge military parade on Saturday 10th, and then an evening concert on the Sunday. In the days surrounding the commemorations though, the appetite to see beyond what was organised and staged was huge, yet rarely satisfied. We were lucky.

If this wasn’t in North Korea, you wouldn’t bat an eyelid. Credit: Lucy Watson

The waterpark felt like no other, yet looked like they all do. When we first entered the building we were not permitted to film but asked to bow infront of a life-size statue of the former ruler Kim Jong Il. This large figure is standing in the foyer of an indoor swimming pool, don’t forget. Weird.

The actual pool area - and when we were allowed to press the record button - is a hot, humid and colourful vision of fun. We saw children, teenagers and parents all splashing about, delighting in what the attraction had to offer.

There were slides, wave pools, restaurants and cafes.

If it wasn’t in North Korea, you wouldn’t bat an eyelid.

The misty view over the capital city Pyongyang Credit: ITV News

The government has poured money into this project, and others like a dolphinarium and a ski resort.

Such projects seem like absurd ventures in a state where electricity and food are often scarce, but its aim is to reinforce a sense of national prosperity. It is the government’s way of showing that North Korea is rich and advanced.

It was opened in 2013 to huge fanfare and a military ceremony.

The complex is being built by our own efforts, believing in our own strength. It is our structure which proves once again that when we are determined to do something, there is nothing impossible.

Kim Jong Un in 2013

He is often called the Master Builder and this water park is one of his creations. He inspected every part of the design himself (reportedly 113 times) and the whole idea is part of his supposed people-priority politics.

Popular hairstyles for men advertised at the salon Credit: Lucy Watson

We were only allowed to film the swimmers at a distance. Our government official said they were shy. The women’s traditional-looking swimwear reinforced that notion, as North Korea’s social norms are among some of the most conservative in the world, and where shows of physical beauty are often discouraged.

When I stopped one woman and asked her what life was like in her country, and what she thought of the park she said she felt "proud and happy being here".

We have a normal life in Pyongyang, and Kim Jong Un had this water park built especially for us. We feel very proud and happy being here. Our state news tells us everything, so we know that our country is the best in the world. There’s no need to go beyond it.

A North Korean woman

For the duration of our visit, we were shown around by an official tour guide who ushered us into the complex’s separate male and female hairdressing salons. She told me they served 30 customers a day, but for the whole time we were there, we saw nobody.

“I like working here,” she told me, “It’s very clean. I get to see everybody too. All my family and friends come here."

We were also shown huge posters of North Korean hairstyles. That of Kim Jong Un’s is apparently the most popular look, our escort told me.

The adulation for their leader and his government are unquestioning… so far, because this country is a relative black hole.

In a country so seldom illuminated, the chance to shed some light on this enigmatic nation feels like a rare glimpse into a mysterious and hidden world, and leaves me with many more questions than answers.

Popular women hairstyles advertised in Waterpark's separate salons Credit: Lucy Watson

Lucy Watson's in-depth report from North Korea will air on ITV's On Assignment on Tuesday 24th November at 10.40pm.