LONDON (AP) ― The opening ceremony is still 11 days away, but for many in London, the Olympics really got started Monday.

Heathrow Airport had its busiest day ever as thousands of athletes ― from Dutch beach volleyball players to Korean gymnasts ― landed with their javelins, bicycles and sails, and moved smoothly through customs.

Motorists grappled with new traffic lanes painted with the Olympic rings and reserved for only official vehicles and dignitaries. At least one American athlete tweeted that his bus got lost on the way from Heathrow.

Smart-looking sailors guarded the gates to Olympic Park, looking so cheerful that visitors would never guess they had been pulled off leave only a few days ago to fill an embarrassing security gap when a private contractor failed to provide enough personnel.

And as the Olympic flame made its way beside the seaside in the resort of Brighton, organizers revealed dramatic plans for its arrival later this week in London. How’s this for an entrance: A Royal Marine carrying the torch will slide down a rope from a helicopter into the Tower of London.

Monday’s excitement all started at Heathrow.

Beneath giant Olympic rings, athletes from 50 nations touched down in what is being described as Britain’s biggest peacetime transport challenge ― the 1940 evacuation from Dunkirk clearly being excluded from the calculation.

There was a feeling of Olympian scale ― the airport was handling some 236,955 arrivals and departures Monday, breaking the record of 233,562, set on July 31, 2011.

Heathrow usually handles 100,000-110,000 arrivals a day, but this swelled to 121,239 arrivals Monday, many of them Olympic VIPs. Another big arrival day will be July 25, two days before the opening ceremony.

“We’ve got into our battle rhythm,” said a cheerful Nick Cole, the head of planning for the games at Heathrow before the arrivals. A former army officer, he has been preparing for this operation for years and brought in reinforcements to make sure all went smoothly.

Heathrow put half of its 1,000 volunteers on duty and created special teams to deal with the oversized gear of the athletes.

A black T-shirted choir outside Terminal 5 belted out Adele’s smash hit, “Rolling in the Deep,” but many were in too much of a hurry to listen.

For once, arriving passengers didn’t shuffle around in seemingly endless immigration queues waiting to enter Britain. Hundreds of agents were on the job to ease the long lines that have plagued the airport for months. Police and their dogs were out in force. Rows of VIP buses whisked teams and coaches to the athletes village in east London.

Everywhere, excited future Olympians were ready for their moment in the London, um, rain. (Even locals have given up hopes that the sun will shine.)

Elisa Liyanage, 14, of France, made a special trip to Heathrow just to hunt for Olympians’ autographs.