Seven things to look out for during the Olympic opening ceremony

With an anticipated 10,000 athletes parading through the heart of Paris, Friday's Olympic opening ceremony promises a spectacle par excellence.

Many of the details have been kept secret, so expect plenty of surprises.

The ceremony begins at 18:30 BST, and will last just under four hours.

Here are some of the things to watch out for during the curtain-raiser, which you can watch live on the BBC.

1. A free-flowing ceremony

For the first time, the ceremony will take place not in a stadium, but in the heart of a city. The world's Olympic teams are set to parade along the River Seine in boats, watched by about 300,000 spectators in a display directed by Thomas Jolly, the ceremony's artistic director.

The flotilla will carry more than 10,000 athletes along a 6km (3.7 mile) route along the waterway, which has been under intense scrutiny for its cleanliness.

• Watch: BBC joins Parisian mayor for a dip in the Seine

Organisers hope Friday's spectacle is free-flowing, amid a mammoth security operation that will involve tens of thousands of police.

Earlier this year, French President Emmanuel Macron admitted that a plan B (and a plan C) had been put together in case the challenges proved insurmountable.

2. The glorious City of Light

The boats will pass some of the city's best-known bridges and landmarks on their journey during the evening - including Notre-Dame cathedral and, naturally, the Eiffel Tower - before reaching the Trocadéro.

It will conclude as the sun sets over the city's west, which organisers hope will further solidify the legend of the City of Lights. Games president Tony Estanguet has promised the timing will make the show "more sublime, with a truly poetic dimension".

(And by the way - theories differ as to whether the French capital earned its nickname as a luminous centre of intellect and creativity, or due to the way it reportedly embraced street lighting early in the technology's development.)

3. Cameras on every boat

Organisers are promising cameras on each boat to show the stars up close.

But what remains to be seen is exactly how this arrangement scales up and down for Olympic delegations of different sizes.

The USA, for example, is sending just shy of 600 competitors while some smaller nations are being represented by just a single competitor each.

Dozens of vessels will be used, with help enlisted from local boat firms.

The spotlight will be shone on those athletes given the job of carrying their team's flag. A pair of British Olympic veterans - diver Tom Daley and rower Helen Glover - have been given that responsibility for Team GB.

Thousands of athletes will travel in a parade of boats along the river Seine

4. Possible rows over music

Jolly has signed up 3,000 performers - including musicians and 400 dancers on bridges - though he's remained tight-lipped about who the famous names are.

It has been suggested that French-Malian R&B star Aya Nakamura could be among the musical acts, as the world's most-streamed French-language artist.

That remains unconfirmed, and has proven unpopular with the French far-right, which has argued that her music owes more to Africa and the US than to France. Nakamura was prompted to reply to one group: "What do I owe you? Nothing."

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There's been some speculation that Canadian star Céline Dion - who sings in French and English - could perform, after she was seen in the French capital earlier this week. Again, nothing is confirmed, but a performance would represent a comeback for Dion, who cancelled shows after revealing in 2022 that she had a rare neurological condition called Stiff Person Syndrome.

Lady Gaga, too, has been spotted going through a routine on some stairs along the River Seine, so we can be pretty confident that she is going to feature.

But Daft Punk fans hoping to "get lucky" with a performance from the French duo were left disappointed when the act shot down any rumours they'd take part.

5. A mystery torchbearer lighting up the show

Paralympic archer Antonio Rebollo lit the Olympic torch in Barcelona in 1992

The Olympic torch travelled to the French capital from Greece in a massive relay that began more than three months ago. As part of its journey, the torch was briefly transported on the world’s longest rowing boat - the 24-seat Stampfli Express.

As for who gets the honour of lighting the Olympic cauldron - tradition dictates that the identity of the final torchbearer stays a secret until the big televised reveal.

That duty has previously fallen to the likes of Muhammad Ali in Atlanta in 1996 and to Aboriginal sprinter Cathy Freeman in Sydney four years later.

Among those who've carried the torch so far are French former footballer Thierry Henry and judo star Romane Dicko. Rapper Snoop Dogg will also have a role in carrying the torch in the final stages of the relay before the opening ceremony begins.

6. A bold array of looks

With the athletes' parade always comes a bold array of looks - not least when the Olympics are taking place this time in one of the world's style capitals.

Team USA and Team GB will be kitted out by Ralph Lauren and Ben Sherman respectively. Other eye-catching outfits come courtesy of Stella Jean, whose designs for Haiti are designed to project a vibrant image of the Caribbean nation.

• Perfect 10? The looks the athletes are sporting

The event's organisers say some 3,000 unique costumes have been made for both the Olympic and Paralympic opening and closing ceremonies in a secretive workshop near Paris. Many will be made of recycled materials as the Games looks to stress its green ethos.

The woman stitching together this part of the visual spectacle is Daphné Bürki, who says she has been getting ready for the "biggest show of the 21st century four times over".

Haiti's colourful Olympic designs have been praised for their originality

7. Royalty - sporting and literal

Keep your eyes peeled for sporting superstars among the athletes' contingent.

But we also expect to see celebrities and dignitaries of all sorts in the crowd, with more than 100 heads of state and government due to attend, according to Reuters.

US First Lady Jill Biden, French President Emmanuel Macron, American singer John Legend and his wife Chrissy Teigen, have already been spotted but could there be bigger names to come?

Queen Elizabeth II appeared at the London 2012 curtain-raiser - and not just in her iconic filmed appearance with Daniel Craig.

• 'Good evening, Mr Bond': When the Queen met 007

How to watch on the BBC

The opening ceremony will be shown live from 17:45 BST on BBC One, BBC iPlayer and the BBC Sport website and app.

You can tune in to radio coverage on BBC Radio 5 Live and BBC Sounds from 19:00 BST.

There will also be live text coverage on the BBC Sport website and app bringing you the best of the event from Paris.