Karl Stefanovic and Jasmine Yarbrough’s wedding in lockdown

A bizarre space age metal structure is being erected on a Mexican beach, giving a giant hint about Karl Stefanovic’s wedding, as security ramps up.

As final preparations get underway, a mysterious giant futuristic metal structure is being set up for Karl Stefanovic’s wedding to Jasmine Yarbrough.

A photo of the structure has been snapped on the beach in Cabo, Mexico giving the first big hint of where the reception will be held in the One&Only Palmilla resort.

Despite a run through of the reception yesterday in a chapel on the resort’s grounds, the bizarre structure likely means the reception will take place on the beach.

The space age set-up looks like it could be the dance floor for guests looking to party into the night.

Wedding guests staying at the Hilton Los Cabos had been overheard earlier talking about a Studio 54 costume party being part of the weekend celebrations.

“I’m all set for the Studio 54 party!” one guest said to another over drinks. “Got my all-white suit.”

Other guests attending the wedding confirmed they have come armed with Saturday Night Fever choreography, but said they didn’t even know when they’d need to bust the moves.

Karl and Jasmine’s futuristic looking reception structure.

That’s a lot of netting.

The beach area at the One&Only Palmilla resort on the morning of the wedding.

CAMOUFLAGED GUARDS

But the couple are going to extreme lengths to keep the party under wraps, with the Mexican marines deployed off the shore of the beachside nuptials.

A Marinas boat is positioned off the coast of the Baja Peninsula with officers interrogating those aboard smaller boats and issuing warnings and threatening arrest.

Security ramped up in the hours before the sunset ceremony with armed Mexican police and hotel staff banning people from the beach that snakes around the front of the exclusive Palmilla resort — the couple’s wedding HQ for the weekend.

With the celebration expected to kick off shortly inside the hotel grounds, some media took to the sea on boats to catch a closer glimpse when the celebrations move to the beach from 5.30 Mexico time for the reception.

The resort is famous for the next level privacy it offers famous guests, and this latest security development is similar to the treatment Jennifer Aniston received when she held her 41st birthday at the resort in 2010.

Photographers aboard boats were deterred with staff on jet skis and a military boat.

Security measures have been escalating all day ahead of this afternoon’s celebration, which is expected to be held at the estate’s grand chapel.

Entrance to the Chapel where the couple will wed later today. Picture: Supplied

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Mexican police, dressed in camouflage uniform and toting guns, were patrolling the public beach that wraps around the front of the legendary resort by 9am — removing any suspected media and threatening arrest.

The resort’s staff are also dotted around various points of the beach, using two-way radios to report the presence of new people.

Most of the almost 200 wedding guests who’ve joined the Today host and his shoe designer fiancee in the desert paradise are being kept in the dark about exact details across the three-day extravaganza. Some confused guests in nearby hotels are asking their concierges if transportation has been organise to pick them up at a certain time for this afternoon’s celebrations.

Stefanovic and Yarbrough embrace his mother, Jenny Stefanovic, during the pre-wedding festivities.

One guest told news.com.au they “know nothing” about the weekend’s schedule and received down to the wire updates detailing times and locations.

“We don’t know anything! We just get these secret texts (saying) ‘be here at this time’,” one wedding guest said.

While the happy couple and a select few of their A-list guests are living it up at t he luxury Palmilla resort — where rooms start at more than $1,000 and go upwards of $30,000 for private villas — other guests are staying down the highway at the Hilton, Westin and Marquis.

A horror car crash this morning involving a flipped car caused major delays all morning bringing traffic to a standstill on the only route from wedding guests’ hotels to the Palmilla.

Unseasonable wet weather on the Baja Peninsula yesterday threatened to taint Stefanovic and Yarbrough’s special day but the couple have woken this morning to blue skies and light winds.

The couple and their wedding parties appear to be relaxed and stress-free about the big day. Some of the male wedding guests were spotted playing a round of golf on the sprawling green at the resort this morning.

Today’s coastal ceremony is expected to be a relaxed affair with lots of personal touches. Some of the details were revealed at a reception rehearsal that took place at the Palmilla’s chapel yesterday afternoon.

The bride-to-be at the rehearsal dinner. Picture: Instagram @mikeybaruch

The sound of an acoustic guitar could be heard coming from the chapel, while someone sang a cover of Oasis’ ‘90s heartbreak hit Wonderwall. Those inside the rehearsal said Karl’s brother Peter Stefanovic was involved in the performance — but wouldn’t confirm if he played the guitar or sang.

The cover of the iconic Brit-pop song could be a form of payback from Peter, after Karl sang a cover of the Oasis hit Champagne Supernova at his wedding to Sylvia Jeffreys last year.

While the song is a touching tribute to Karl and Jasmine’s relationship, it’s also a cheeky wink to the Stefanovic brothers and their Uber-gate scandal that plunged them into hot water earlier this year.

In the embarrassing phone call, the brothers reportedly compared themselves to troubled Oasis brothers Noel and Liam Gallagher because of their fractured relationship with their father.

Despite the years-long rift, Alex Stefanovic insisted to reporters yesterday he had mended his relationship with his oldest son.

The couple were joined at the rehearsal by their families and large bridal parties.

Some major A-list no-shows have taken away some of the star power the original guest list promised. James Packer, Alan Jones and Kyle Sandilands have all stayed home. But some familiar faces are still attending.

Former foreign minister Julie Bishop and partner David Panton were seen whizzing around the resort with the fitness fanatics checking out the health and wellness facilities.