WARNING: Vague spoilers ahead.

If you've read George R. R. Martin's "A Song of Ice and Fire" series, or at least his third book "A Storm of Swords," you know what that the so-called Purple Wedding is coming on season 4 of "Game of Thrones," and behind-the-scenes writer Cat Taylor recently gave some filming details of the big event.

"While the ceremony itself was filmed in one of our semi-permanent sets in Belfast, the Sept of Baelor, the reception was filmed in a beautiful outdoor set located in Parc Gradac in Dubrovnik, Croatia," Taylor wrote in her online production diary. "The park was transformed by our new Production Designer, Deb Riley, and her team into everything you might desire from a Royal Wedding carnival, with elaborate decorations, an epic feast and the most creative and unexpected forms of entertainment for the guests."

"Filmed over a five day stretch, we waited with bated breath each day for the clouds to roll in and dampen our fun. Weather reports suggested imminent downpours at the end of the week, and only a few days before, water funnels had formed off the coast in the height of a rain storm. Aside from one short and dramatic burst where Costume scrambled to get all the extras under cover and everyone rushed to protect props, we were spared the worst of the predictions."

The Purple Wedding, as it's known by fans, or Royal Wedding as Taylor refers to it as, is a "Game of Thrones' event that is sure to shock thousands of viewers. Last month, Martin teased to TV Guide that "it's going to be the wedding of the year, and as memorable in its own way as our wedding last season," the infamous Red Wedding.

"In terms of principal cast members in attendance, the Royal Wedding was one of the largest scenes we've filmed since the premiere season, with 23 named parts appearing on any given day," Taylor wrote. "In addition, we were delighted to welcome 218 extras as guests to the event, some of them travelling from the other side of Europe and the United States to be a part of the experience. Lookout for some familiar faces in the crowds - Pixie Le Knot is back this year, and one of our crew makes an appearance with the entertainers."

Season 4 of "Game of Thrones" premieres Spring 2014 on HBO, and very soon, a series of trailers and promos will be released to rouse fan excitement. The third season will also be available on DVD and Blu-Ray in February.

Click here to see a photo of a crew member preparing (or cleaning up) the set of the Purple Wedding.