An exhibition aiming to delight both children and adults this coming Christmas season opened Monday in Spain's capital for the latest leg of its current global tour, the first-ever that has been authorized by Denmark's Lego group.

The exhibition held at Madrid's Palacio de Gaviria, titled "I Love Lego," showcases six large-scale, painstakingly detailed "Legoramas" that were first exhibited in 2016 in Italy, where the display created a huge sensation and was visited by around 500,000 people.

"This is an unprecedented exhibition in Spain," said Jesús Rodríguez, director of the Palacio de Gaviria exhibition hall, while underscoring the "extreme difficulty" involved in creating the six Legoramas, which each took a week to assemble.

Visitors can now marvel at miniature versions of the Roman Emperor Augustus' Forum, an Italian alpine village of Tyrol or a castle inspired by the "Game of Thrones" fantasy TV show.

Overall, the exhibition has used over one million Lego bricks.

The event, which was organized by Arthemisia España, was made possible thanks to the detailed montage and assembly by members of RomaBrick – one of the oldest so-called LUG (Lego User Group) associations – who garnered a resounding success last summer after the exhibition visited Seoul (South Korea).

Other brick-by-brick recreations include a skyscraper megalopolis, a Christmas-inspired dream village and "Operation Nakam" (a little known Jewish partisan militia episode during World War II), each lovingly built by RomaBrick teams comprised of three volunteer engineers and architects specialized in Lego construction.

The assemblies include several "Easter eggs" that include hidden figurines depicting pop culture icons such as Batman and Superman, the Ghostbusters' vehicle or a Star Wars spaceship that kids and adults will try to discover.

Rodríguez underscored that each of these installations needed six months to one year of prior planning and their complex set-up required massive attention to detail.

"I Love Lego" is set to remain in the Spanish capital until Feb. 24, 2019.