Editor's note: After Kim Jong Il's death brought tears in North Korea and caused concern for South Korea, we're taking a look at the secretive nation from the view of those who have traveled there.

The first time that Brit Simon Cockerell visited North Korea, he noticed how clean it seemed. The air was not polluted like in Beijing, where he has lived since 2000. Another curiosity also struck him: In the capital of Pyongyang, there were no advertisements or billboards, and there was no traffic.

One of the rare times one might see North Koreans out and about during the day is when co-workers are doing aerobics with their "work unit" in the morning, he said. Around lunchtime, workers might venture outside again, perhaps stringing up a net or marking a line in the street to play a quick match of volleyball before returning to the grind.

"It's a place that can seem very dead during the week. There are a few bars in Pyongyang, but they close around 10 p.m. There are no crowds. And this is odd, because there are 3 million who live in that city," said Cockerell, who has visited North Korea more than 100 times.

"There isn't any hustle or bustle. Everything is a five-minute drive away. You wind up, typically, on your first day saying to yourself, 'Bloody hell, I'm in North Korea, where is everyone?' "

North Korea's is a working society, he said. The workweek is six days, and children are often in school. "On the weekends, you might see people in parks, though," Cockerell said.

But all that work does not equal advancement or personal riches.

"It's an exceptionally poor country," he said. "People don't spend money because they don't have it, and there's not much to buy anyway."

Cockerell works for the China-based tourism company Koryo Group. British ex-pat Nicholas Bonner, who also lives in Beijing, co-founded the company, which offers tours ranging from two-day visits to Pyongyang to 16-night trips across the country. The typical Koryo client is highly adventurous and well-traveled. North Korea is a much-desired passport stamp for many travelers, the company  says.

"There are people who go to North Korea expecting to be spied on, and they make up their minds that it's going to be dramatic," Cockerell said. "I hate to spoil someone's sexy story, but there's no way to tell if that's happening. Visitors experience the place the way they want to experience it. So you see an odd-looking man across the street whose gaze is lingering a bit too long. Is he a spy? Would it be more interesting if he were? There's really no way to know. You can't ask someone and get an answer, which, of course, to some people heightens the mystery."

One reason there are very few cars is because fuel is imported and, consequently, very expensive. Leisure, drinking and dancing are not forbidden, but most people spend time at home with friends and family, he said. And the lack of pollution isn't indicative of a government that's cooperating with air quality regulations.

"It means that there's no industry and that the economy is suffering," he said.

In recent years, Cockerell has noticed that Chinese wholesalers are selling clothes to North Koreans. "The clothes are cheaply made, but they have some element of style. People will hang a bit of bling off their cell phones," he said.

Tourists can't accessorize their mobile phones because they must surrender them before entering the country and get them back when they're leaving, Cockerell said. But iPads, computers and digital reading devices like Kindles are allowed. "This policy doesn't make sense, but it's been around for many years," he said.

Koryo gives tours of North Korea to about 1,500 tourists every year, including a two-day visit for about 700 euros. A 16-night adventure is available for many thousands more. During a longer trip, Koryo can charter a private plane to fly to the west coast and along the DMZ, then head to the northeast coast, where tourists can stay with a North Korean family in a structure built for tourists.

Most of the buildings in Pyongyang are boxy and dully designed. The city is dotted with oddly placed gigantic monuments to the government. Pictures of leader Kim Jong Il are tacked everywhere.

While there is no organized religion in North Korea, there are a few churches in Pyongyang, Cockerell said.

The closest element to a religion was devotion to Kim, whose death was announced Sunday.

"I'm sure the devastation that people feel today is tremendous," Cockerell said.