Lydia Hearst celebrates epic bachelorette party at Hearst Castle

As a publishing princess – she's the great-granddaughter of William Randolph Hearst – model, actress and heiress Lydia Hearst chose the perfect place to celebrate her bachelorette party: Hearst Castle in California. Set to marry her TV producer fiancé Chris Hardwick soon, the bride-to-be was joined by her closest girlfriends, including her former Gossip Girl co-star Michelle Trachtenberg. Click through to see the highlights of the lavish bachelorette bash!

Lydia Hearst: "Floaties & ladies in the Roman Pool  photo by @selkiehom#HearstCastle #GirlsWeekend #LydiaHearstCastleBacheloretteWeekend"Photo: Instagram/@lydiahearst

Michelle Trachtenberg: "Private evening at @thehearstcastle! We came. We saw. We swam!!! Thank you to my bestie, #bride to be, @lydiahearst for an experience I will never forget, I love you!! I can't wait for the #wedding! #hearstcastle #bachelorette #hearstwick ✨濾✨"Photo: Instagram/@michelletrachtenberg

Michele Morrow: "This adorable vintage swimcap, courtesy of the bride, ended up perfectly matching my new @toripraverswimwear #swimsuit! #Hearstwick"Photo: Instagram/@michelemorrow

Michelle Trachtenberg: "Private tour of the #hearstcastle? Don't mind if I do. This is the magical screening room. Just another awesome activity for @lydiahearst's #bachelorette weekend. #hearstwick ✨"Photo: Instagram/@michelletrachtenberg

Clare Grant: "Lydia said I could move in to this room at her family's castle as long as I wore the pink dress on the bed and fed her cotton candy while singing the national anthem. I'd say it's a fair trade. #HearstWick #HearstCastle"Photo: Instagram/@Claregrant

Kris Zero: "So stoked for my girl @lydiahearst epic castle magic weekend! Love you so much!!! T minus 3 weeks!!!!! #hearstwick #bachelorette   @nikkipennie"Photo: Instagram/@kriskriskris

Barbara Adler: "Lydia's bachelorette weekend has begun #hearstranch #hearstwick #lydiabachelorette "Photo: Instagram/@barbara_s_adler

Michelle Trachtenberg: "Just #horsing around at @lydiahearst's #bachelorette weekend. #hearstwick ✨"Photo: Instagram/@michelletrachtenberg

Amanda Gullickson: "Hearst Ranch for a girls weekend with the bride to be @lydiahearst  #bacheloretteweekend"Photo: Instagram/@amandalgullickson

Lydia closed the weekend with a sweet Instagram post which read in part, "Thank you so much to all my my girlfriends who came away with me to celebrate my love and upcoming marriage to @hardwick. I cannot imagine having a group of more kind, lovely or generous friends... This weekend was truly magical and would not have been the same without each and every one of you. I love you all!!!  "Photo: Instagram/@lydiahearst

Michelle Trachtenberg: "#latergram Been so busy enjoying @lydiahearst's fabulous #bachelorette weekend, I haven't had a moment to post, because I've been in the moment, stay tuned for more. Started at the #MadonnaInn for breakfast....#hearstwick #lydiahearstcastlebachelorette weekend. 濾"Photo: Instagram/@michelletrachtenberg