Jeff Bezos and Lauren Sánchez Spark Uproar With Ultra-Secretive Venice Wedding—Guests Left in the Dark, Security on High Alert, and Rumors Flying! What Are They Really Hiding? The Mysterious Measures, Lavish Surprises, and Shocking Demands That Have Everyone Talking—Is This the Most Controversial Celebrity Wedding Ever?

A source tells PEOPLE guests were given instructions regarding what time to be ready, but not information on where they would ultimately be heading

Jeff Bezos And Lauren Sanchez.Credit : Ernesto Ruscio/GC Images

Jeff Bezos and Lauren Sánchez are keeping their wedding details under wraps until the last minute — with even guests in the dark about where the ceremony will take place.

A source tells PEOPLE guests of the wedding, which is being held in Venice this week, were given instructions regarding what time to be ready, but not information on where they would ultimately be heading for the ceremony.

The wedding of the Amazon founder, and the former journalist has been mired in secrecy — in part, due to security precautions being taken by the couple.

As the event nears, ongoing protests have cropped up across Venice, with posters, stickers and signs around the canal city’s historic center reading “No Space for Bezos.” Greenpeace, a global environmental organization, recently deployed a giant banner at St. Mark’s Square displaying a picture of the Amazon billionaire laughing alongside the words: “If you can rent Venice for your wedding you can pay more tax.”

Already, there have been some changes in the celebrations.

A source tells PEOPLE that the wedding party originally planned on June 28th at Scuola Grande della Misericordia, a medieval former religious school in Cannaregio, has now been moved to a new location due to protests and safety concerns.

The expected 200+ guests — many of whom are A-list celebrities — will instead celebrate in a hall at the Arsenale, a large 14th-century complex in the eastern Castello district, which is surrounded by water and unreachable by land when connecting bridges are raised.

Jeff Bezos and Lauren Sanchez.COBRA TEAM/BACKGRID

A source earlier told PEOPLE that security preparations for the Bezos-Sánchez wedding have transformed Venice into a “fortress-like operation,” as approximately 20 security personnel were “stationed and in full operational move” across one of the key venues for the couple’s celebrations: a closed cloister adjacent to Chiesa della Madonna dell’Orto, a Catholic church in Venice.

On Tuesday, June 24, several celebrity guests began arriving in Venice. Among those spotted in the Floating City were Ivanka Trump and her husband Jared Kushner. Diane von Fürstenberg was also seen arriving at Venice’s Marco Polo airport on the same day, with Corey Gamble following one day later.

Jeff Bezos and Lauren Sanchez in Venice.COBRA TEAM / BACKGRID

Bezos and Sánchez themselves were pictured stepping off a boat together in Venice and arriving at the Aman Hotel on Wednesday, June 25.

Earlier on Wednesday, PEOPLE confirmed that the billionaire tech founder and his fiancée had touched down in Venice.

A helicopter left Venice on Wednesday midday local time, landing on Bezos’ yacht’s support ship, named the Abeona, next to Bezos’ yacht, Koru, which was parked just off the coast of Croatia. The chopper then returned to Venice with the couple aboard. The helicopter landed in the Venice Lido, where the city’s annual Venice Film Festival is held.