Below, Olivier tells CNN Style what he found "seductive" about Pyongyang -- from locker room tiles to the city's homogeneous use of concrete.

What are the particular challenges in architecture photography? What makes a photo of a building weak, and alternatively strong?

This is a vast subject. I could talk about it for a long time. It's similar to a portrait. You can photograph a good-looking person, but it could be a bad portrait if there were no emotional charge. On the contrary, if you photographed an unpleasing person, but if something happens with their eyes, posture...this could be considered a great portrait.

Architecture is the same. It's a seduction game between the photographer and subject. If the photographer is seduced by what he sees, then there's an emotional charge. Outside factors like light, angles and lenses also play a big role in architectural photography. It depends on what the photographer feels in front of the structure.

What then did you find seductive about architecture in Pyongyang?

I have never felt as impressed as I have been (in North Korea) in front of buildings, spaces, and built spaces. It's very special there. Because there are no advertisements, billboards, little coffee shops, stuff around -- nothing really distracts from the structures themselves. Everything is massive concrete and there's a strong energy radiating from all these buildings.

Also, the planning of the city is so unique. It's all so symmetrical and well laid out. This, along with the structures and harmony of colors, is hard to explain to somebody who hasn't been there. But I tried to get some of those scenes through my pictures.

Was there anything that surprised you about Pyongyang?

It wasn't my first time in Pyongyang, so I did have an idea of design and a first impression of the city. But I think it's difficult to portray the whole atmosphere -- the small details, sounds, the people, when you're shooting in North Korea. It's so radically different and special.

I would like to do recordings when I go back. Just to capture some of the eerie, melancholic music that's played in the streets. You can hear it all around town. It's dreamy in a really 1950s way. Your senses are on a whole other plane and I think it's hard to translate that to pictures. Sound contributes to how you perceive the space around you.

What are some things that struck you about North Korean architecture that you haven't seen elsewhere?

When you go to any post-Soviet city, you have these vintage elements -- round design, retro-futuristic styles, (the use of) concrete and steel. So you can see these buildings in Moscow, eastern Europe and central Asia, but they are kind of isolated or dissolved in up-to-date architecture.

In North Korea, it's an ocean of this type of architecture. There are only massive concrete blocks with funky designs. They paint with nice pastel greens and yellows, reds and pinks. But they don't have technology to do really other types of buildings. So everything is concrete -- even the pyramid tower (Ryugyong Hotel).

To have a city of only that, the sheer number, the scale, the homogeneity is more impressive because there are so many of them and only them. There's nothing to break the rhythm. There's no alternative.

There's a noticeable absence of people in your photos. Was this intentional?

It's not a very busy city. There's not a lot of traffic, outdoor activities, or a lot public spaces that are used for daily life. It's pretty quiet.

Also, the places we went to visit were very specific buildings, avenues and streets. I would frame in a way where the building would stay pure. Sometimes I would include a little people, to give a sense of scale and a bit of dynamism to the images.

But, visually, I like this style of having images deserted, and more focused on space. And the city is actually quite quiet.

You were taken around as part of a tour group. Did time constraints affect your photos?

It was definitely more rushed than other projects. The group was small and relaxed, only four people. We had 15 minutes to half an hour per site.

I would have liked to explore more neighborhoods but there's only so much you can do in a certain given time. There's no time to shoot on tripods. I couldn't have taken (photographs) on a film camera -- this was a snapshot type of photo shoot.

In your personal projects -- why are you drawn to more remote locations?

When you work commercially for six months, you need to get your head out of that. So I travel around, get fresh air.

For me, I'm more impressed by these type of places. Thailand by the beach is okay. But I think I will always look for visually unique places -- ones with a very special vibe. Places where you can stand there and feel 'wow, this is amazing, what I'm seeing now?'