Touring Westeros by Bus, 'Game of Thrones' Fans Seek Sights and Spoilers

Tourists visit the Giant's Causeway in Northern Ireland, a UNESCO World Heritage Site, in June 2013. The HBO series "Game of Thrones" has filmed extensively on location in Northern Ireland, and the success of the series has attracted a growing number of sightseeing, and spoiler-seeking, visitors as a result. Hazel Thompson/The New York Times/Redux

On a cold, windy morning, on top of a frost-capped hillside overlooking the sea, a small, shivering group of people gathered around a large rock. The ice on the ground crunched as a Chinese tourist wearing a long black cloak with fur trim knelt and stretched her neck toward the rock, as a great sword rose above her head.

Fortunately for Cawei Hua, a 24-year-old visiting from Shanghai, the sword was plastic, the cloak a borrowed prop, and the hillside—in Cairncastle, Northern Ireland—is a regular stop on one of the many location tours celebrating the George R.R. Martin book series that became the HBO fantasy show Game of Thrones. The stone in Cairncastle marks the point where Ned Stark, played by actor Sean Bean, executed a deserter in the show's first season. In the nearly six years since that scene was shot, the series has become a global phenomenon (its sixth season premieres on April 26), and Northern Ireland—where the majority of the show's production takes place—has reaped the rewards.

A popular location on the tours is Cushendun Caves, located below the coastal village of Cushendun and formed over 400 million years by Northern Ireland's harsh weather. Here, the red sorceress Melisandre, played by Carice van Houten, gives birth to a magic "shadow baby" in the show. The caves are also the only entrance to the local convent, where nuns are likely confused to see tourists regularly re-enact the scene for photos. For Hua, these tours are a chance to see an often overlooked part of Great Britain while geeking out at the locations of a show she and millions like her watch back in China.

Millions of tourists now flock to the country, many to see the locations made famous by Game of Thrones, embarking on eight-hour bus tours that stop off at castles, hills, caves and beaches to grab scenic selfies complete with swords and shields. The level of fandom has presented the production with challenges. Though the book series by Martin, called collectively A Song of Ice and Fire, has so far dictated what happens in its small-screen adaptation, the show will overtake Martin's novels in the upcoming season. Though keeping the two stories aligned isn't a problem (Martin has helped write the screen adaptations so that, when he does finish the new books, the two will still basically match), the fact that the show will now presage the books has sparked even more intrigue among the already obsessive fans, who hunt compulsively for hints, sneak peeks and outright spoilers.

At the peak of summer, when the show is being filmed, Robert Boake, Northern Ireland location manager for Game of Thrones, says the crew turns away an increasing number of buses, up to seven per day, all looking to catch a glimpse of future events in Westeros, the fictional country where the show is based. "We have more paparazzi following us around," says Boake, who adds that "drones are an increasing problem. Now we have to consider when we're filming that people would be very interested in seeing what the plotline might be. We definitely get followed around more than we used to."

Northern Ireland might seem like a random place to produce a hit TV show, but for the Game of Thrones creators, who needed passably medieval settlements and sweeping landscapes, the country was well-equipped and easy to access. It also didn't hurt that A Song of Ice and Fire author Martin based many of the novel's geographical descriptions on places in the United Kingdom.

For a small country, landing the production for a huge hit can be a windfall. The most famous example of the magic of movies on a nation's gross domestic product was Peter Jackson's wildly successful Lord of the Rings trilogy (and the subsequent Hobbit trilogy), which made New Zealand the fantasy landscape de rigueur. In the year leading up to September 2001, three months before the release of The Fellowship of the Ring (the first film in the initial trilogy), New Zealand reported earnings of $5.3 billion from international visitors. In the year before March 2014, the country earned $10.3 billion from tourists. Though it's hard to measure whether that increase was directly related to Lord of the Rings, according to Forbes, at least 80 percent of tourists there understood that the two trilogies were filmed in the country, even if it wasn't the only reason they cited for visiting. That's not to mention the amount spent by productions—both Lord of the Rings and those that came after—on New Zealand's small businesses.

The forest floor of Tollymore Forest in Northern Ireland is covered with fake snow for the filming of the first episode of Game of Thrones. Stephen Barnes/Alamy

Eight years ago, Northern Ireland made a gamble on Game of Thrones having the same effect on its GDP. Northern Ireland Screen, a government-backed agency that aims to boost the amount of film, television and digital content produced in the country, first met with HBO in 2008 to discuss Game of Thrones. To incentivize the network to anchor production of the series in the country, Northern Ireland Screen ultimately footed the bill for $4.6 million of the production of the pilot and first season. The investment alone returned about $30 million worth of expenditure on goods and services back into Northern Ireland's economy. As of last year's fifth season, Northern Ireland Screen had invested a total of $17.6 million in the show, with a return of $162 million spent by HBO cast and crew on hotels, transport and other production costs.

Those figures don't include the money generated by tourism. Although the financial impact of Game of Thrones is not documented by Northern Ireland's tourism organizations, the large number of tour companies that have started operating since the show premiered (none of which are affiliated with HBO) is a good indicator of its effect on the industry. Many visitors go to Ballintoy, a small fishing town on the country's north coast, where the show's Iron Islands scenes are filmed, or to Carnlough Harbor, where the actress Maisie Williams (Arya Stark on the show) was recently spotted filming scenes for the sixth season. Some tours, like the Thrones and Stones group, also take in some of the country's tourist attractions yet to be featured in the show, like Giant's Causeway, where basalt columns rise out of the sea at the bottom of spectacular cliff faces, and Carrick-a-Rede Rope Bridge, a rope walkway suspended hundreds of feet above the sea.

More than just benefiting the tourist trade, the show has also created opportunities for existing film talent, leading to the emergence of new filmmakers and writers. Northern Ireland Screen credits Game of Thrones with instilling enough confidence in potential investors to build two new film and television soundstages in Belfast, the country's capital.

As a result of the show's success, more production projects are coming to Northern Ireland, like the Universal Pictures horror movie Dracula Untold and the BBC's ongoing serial killer drama The Fall. But it wasn't always so appealing. Northern Ireland Screen's Richard Williams recalls a time before Game of Thrones, when his organization would go to L.A. and London to drum up interest in filming in the country. "In L.A., we got a total blank. In London, maybe not a total blank but not exactly a joyous reception," he says. "If the people we're talking to now know nothing else, they will know that Game of Thrones is anchored in Northern Ireland. That gives us a credibility platform that wasn't there before."

"The Game of Thrones machine is much, much bigger than it was back in the beginning," says Boake. "The production size and scale of what we're doing and the level of ambition every year have definitely increased." Boake's locations team has grown from five people eight years ago to 20. "You'll see more cranes than ever before—more trailers, trucks, people, horses, marquees."

The upcoming sixth season of Game of Thrones is already set to include the biggest battle scene of the series so far, show writer and producer Bryan Cogman recently told Entertainment Weekly. Any information about the scene hasn't leaked, but it's rumored to include hundreds of extras on either side and will no doubt create a new stop for future tour groups—plastic swords and all.

Two more books in A Song of Ice and Fire are yet to be released, though it's unclear how many seasons of the show will follow. HBO has renewed Game of Thrones through the eighth season (its creators have said they don't see it continuing far beyond that), yet one of the quarries in Northern Ireland that the show uses regularly for shooting has reportedly been leased for 15 years. Regardless of when the show does end, the drones and spoiler-seekers may leave, but as New Zealand can attest, the benefits to the country's film and tourism industries will remain.