When Paul Cox first started taking photos in Mongolia, he had to ensure his camera would stay hidden.

As a foreigner there to document the economic hardships endured by locals in the Chingeltei district of Ulaanbaatar, he was initially met with suspicion and distrust. His camera would alert his status as an outsider.

But after partnering with a local charity group, he was soon able to not only witness, but also capture the locals' most private moments -- documenting what he says is an unforgettable welcoming warmth in the Mongolian community.

paul cox

The images captured since his first visit produced three full exhibitions. The most recent, Red Hero 3 , went to auction in partnership with Christie's in Hong Kong this week.

Speaking to CNN Style, Cox reflected on his experiences documenting life in Mongolia.

CNN: Why did you decide to start photographing life in Mongolia?

Paul Cox: Someone I had previously worked with invited me to photograph there.

When I landed, I had no preconceived ideas about what it would be like. Tourists usually go to the countryside, but I was going to the city.

paul cox

My initial explorations involved jumping into a taxi, pointing at directions I wanted to go, and yelling "Stop!" when I wanted to take a photo.

I had no real agenda or route in mind.

I was then introduced to the j, which invited me to photograph within the inner city itself.

This opened a whole new world as it granted me access to the private lives of locals.

CNN: What was your experience like in these communities?

Paul Cox: In weather conditions that hit -20 degrees or lower, people in the poorer areas of the city have no access to running water, no access to bathroom facilities, often living in little "yurts" or "gers" on dirt roads.

paul cox

The community is nice once you get to know them, but I realized it can be very dangerous for foreigners.

As an outsider with a camera, I came across several altercations.

While roaming local market places, I not only felt the distrust from locals, but on several occasions locals attempted to punch me.

This frustration towards me, according to some locals that I spoke to, has as much to do with my camera as it does with me being a foreigner.

paul cox

In the city areas, there is a very high unemployment rate, and as a foreigner, I represent the wealth that is being taken out of the country.

My camera also caused me problems because locals did not want their poor state of living to be photographed, due to a strong sense of pride.

CNN: Why did you feel it was important to take these portraits?

Paul Cox: What I saw was very different to the beautiful images people see of countryside -- the eagles, the sweeping planes of the desert.

My images are far from the standard representations of Mongolia.

CNN: How do the city and countryside compare?

While the city can be a hostile place for foreign photographers, the countryside and its beautiful people are some of the warmest most friendly people I have ever met.

I put this to the nomadic people, who have a strong identity here, a sense of purpose, and clearly defined gender roles.

I believe that many in the city have lost this in some ways.

The roles have become blurred, alcoholism is rife, unemployment is around 60%. This stress creates this distrust, anger and social issues in my opinion.

CNN: Have you faced any specific challenges trying to get the perfect shot?

Paul Cox: One summer I was driving for six days to the border of Siberia to photograph the reindeer people (who use reindeer instead of yaks or cows.)

paul cox

The land was vast and boundless, most of the bumpy roads don't show on Google maps, our car broke down so often that we needed to bring an extra vehicle on the ride. And at one point -- in June -- it suddenly started to snow.

Everything is unpredictable.

CNN: What photograph stands out to you most in this exhibit?

Paul Cox: The defining photo is "Red Hero 3."

The child in this photograph, we saw him by chance because we crossed paths when he was playing, and he was looking at me. He was an adorable child who was completely unafraid of strangers.

We engaged in a conversation with him and his family, and realized that his family has been struggling with the boy's epilepsy.

The photograph I took of him shows a wolf carpet on the wall, which is said to be used for both warmth and decoration. The wolf, very symbolic of Mongolian culture appears to stand guard over our hero. To me it speaks of the responsibility of the viewer and as a society to look after our future.