Onlookers held up umbrellas to protect themselves against driving rain as they tried to look over a pastel coloured synthetic canvas set up around the gardens of the Real Alcazar palace. The barrier was set up to keep plot details of the Home Box Office series secret.
The palace, a masterpiece of Islamic architecture in old Seville packed with columned courtyards and elaborately tiled halls, said on its website that it will undergo "partial closures" until the end of October during the filming of the series.
Producers have reportedly obtained special permission to tint the waters of the pools of the palace's courtyard gardens dark blue for one scene of the fifth season of the series, which started filming in Northern Ireland earlier this year.
They will use an eco-friendly product that evaporates several days after being used in the water, according to daily newspaper ABC.
The Real Alcazar is one of Seville's top tourist attractions. It draws over 3,000 visitors a day. The oldest parts of the sprawling complex date back to the 10th century.
Seville, with its picturesque alleys, hidden plazas and flower-decked patios, already draws about two million tourists a year and local officials are optimistic that the series will bring even more visitors.
"We will have to endure some inconvenience, taking into account the possible generation of jobs and the impact on tourism that this will have," Seville mayor Juan Ignacio Zoido told reporters earlier this week.
The Croatian city of Dubrovnik, where three seasons of the popular show were filmed starting in 2011, reported a jump in visitor numbers after the episodes aired and special "Game of Thrones" location tours sprung up.
Season four of the series, a tale of battles and betrayal mixed with a generous helping of sex and bloodshed, averaged 18 million weekly viewers in the United States, making it one of the most watched series on television.
After filming wraps up in Seville, the crew will later this month move on to Osuna, a small hilltop town surrounded by olive groves located about 80 kilometres (50 miles) away which will reportedly serve as the backdrop for a battle scene.
Osuna city hall says visitor numbers to the town are already up by around 15 percent since producers of the series announced at the start of July that it would film part of the fifth season there.
Hotels in the town of around 18,000 residents are fully booked during the second half of October when filming is expected to take place, while a tapas bar in the town has introduced a special menu with dishes named after "Game of Thrones" characters.
As Spain grapples with an unemployment rate of 24.5 percent, the second-highest in the European Union after Greece, producers did not struggle to find extras seeking a few days work on the set.
Producer Fresco Film services based in Malaga said it received over 86,000 applications to audition for extra roles.
The company selected 4,000 people to come to auditions and will hire 550 people to work as extras per day over 17 days of filming, said the company's executive producer Peter Welter.
Police in July detained two men in Ibiza who ran a fake website that instructed people interested in work as extras to call a premium telephone line operated by the pair that put callers on hold for several minutes.
Police suspect they earned as much as €100,000 ($127,000) in a week with the scam.