North Korea was a final frontier for Google Maps.

It took years and the help of amateur map-makers who once lived there or knew people who did to add gulags, streets and other details to what was long a patch of gray at the online atlas.

Updating the map of North Korea promised on Tuesday to be the beginning of Google pulling back the curtain on the lay of the land in the notoriously isolated state using the power of the crowd.

"North Korea was the last place that we had no mapping data," said Google Asia-Pacific head of product public relations David Marx.

"Our mapping team is not happy until they have a true mirror of the world in digital space, so the challenge is still there and we will keep working."

North Korea was essentially a blank canvas to users of Google's "Map Maker," which gives people tools to enhance online maps with knowledge of local venues, roads, businesses, landmarks and more.

"Citizen cartographers" have been uploading suggested edits to Google's online map of North Korea since 2009 and a time-lapse video of details emerging about the capital Pyongyang was uploaded to YouTube in October of 2011.

The snippet at the Google-owned video sharing service had logged 1,402 views as of Tuesday.

The collaboratively created map of North Korea now on display at Google offers a detailed layout of Pyongyang, showing hospitals, subway stops and schools.

Outside the capital, the detail is sketchier, but noticeable on an overview of the country are a series of city-sized, gray-colored areas which, when zoomed in on, are identified as sprawling re-education camps.

"For any of our Map Maker countries - whether India or North Korea - we rely on users' knowledge of a place, and Moderators use a variety of sources to verify user edits," Marx said.

"All changes are moderated and most of them are reviewed by fellow mapping volunteers in the Map Maker community," he continued.

Greg Scarlatoiu, executive director of the Washington-based Committee on Human Rights in North Korea, said that much of the data on the maps was already available on Google Earth.

The information generally came from defectors or human rights groups that tried to expose developments in the opaque state, he maintained.

"This is overall a positive development, but it is not a major breakthrough," said Scarlatoiu.

"Any additional information is welcome," he continued. "The problem we have is that, unlike in Sudan for example, we do not have visual images from North Korea."

The people least able to benefit from the improved online map of the country will be the North Koreans themselves, who live in one of the most isolated and highly censored societies on the planet.

North Korea has a domestic Intranet, but it is cut off from the rest of the world, allowing its very limited number of users to exchange state-approved information and little more.

Access to the full-blown Internet is for the super-elite only, meaning a few hundred people or maybe 1,000 at most, experts estimate.

Internet Age mapping technologies have proven to create jobs and stimulate business, and North Korea stands to benefit from embracing such digital tools, according to Google Maps policy analyst Charlie Hale.

"Embracing mapping in North Korea would lead to economic benefits," Hale said. "It lays a crucial foundation and infrastructure that you can build on."

There was no indication from Google that it had heard any reaction to the updated North Korea map from government officials there.

Google downplayed the timing of the North Korea map update, which came shortly after a secretive visit to the country by the California Internet titan's chairman, Eric Schmidt.

Schmidt has openly decried what he fears is the "balkanization" of the Internet by countries that cut users off from the rest of the world.

Schmidt's teenage daughter shed some light on the trip less than two weeks ago by writing a first-hand account of the visit to a "very, very strange" country.

In a blog posting entitled "It might not get weirder than this", Sophie Schmidt provided a candid take on the controversial three-day trip earlier this month that was criticized by the US government.

Schmidt, 19, had accompanied her father on the visit as part of a delegation led by Bill Richardson, the former US ambassador to the United Nations.

"Our trip was a mixture of highly-staged encounters, tightly-orchestrated viewings and what seemed like genuine human moments," she wrote.

"We had zero interactions with non-state-approved North Koreans and were never far from our two minders."

On his return, Eric Schmidt said he had told North Korea it would not develop unless it embraces Internet freedom -- a prospect dismissed by most observers as inconceivable.

Google did not indicate whether Schmidt or his daughter contributed to the updated online map of North Korea.