London celebrated the one-year countdown to the 2012 Games with the first dive into the new Olympic pool, the presentation of medals and a call to the world's athletes to compete in the country that "invented modern sport."
Exactly one year from Wednesday — on July 27, 2012 — London will be staging the opening ceremony of the Olympics, the first city to host the world's biggest sports festival for a third time after previous games in 1908 and 1948.
In a live televised ceremony in Trafalgar Square, IOC President Jacques Rogge formally invited 202 national Olympic committees from around the world to send their athletes to the British capital.
"The athletes will be ready, so will London," Rogge said.
The ceremony took place in the same square where thousands of people celebrated on July 6, 2005, when Rogge opened a sealed envelope in Singapore and announced that London had won the right to host the Olympics, beating rival bids from Madrid, Paris, New York and Moscow.
"A dream was born when the IOC awarded the 2012 Games to London," Rogge said. "The world's finest athletes began dreaming of competing in this magnificent city, in packed state-of-the-art venues, and in front of passionate crowds.
"As in 1908 and 1948, they knew they would be coming to the nation that invented modern sport and the concept of fair play."
The festivities started across town at the new, gleaming aquatics center in the Olympic Park in east London, where 2009 world champion Tom Daley performed the first dive into the pool, knifing cleanly into the water off the 10-meter board with an inward 1½ somersault pike.
"It was great — a bit cold actually," Daley said. "It's going to be awesome next year.'"
A few minutes later, several former British Olympic athletes — including javelin throwers Steve Backley and Tessa Sanderson and 400-meter runner Roger Black — took part in the first "race" in the pool. Olympic swimmer Mark Foster was the easy winner.
The ceremony also featured the unveiling of the Olympic medals by Princess Anne, an IOC member and former Olympic equestrian competitor. The medals are the biggest for a Summer Olympics — measuring 3.35 inches in diameter and weighing 13.2 to 14.1 ounces.
Designed by British artist David Watkins, the medals feature Nike, the Greek goddess of victory, on one side. On the other is a complex image containing five symbolic elements, including the River Thames. During the games, 2,100 medals will be awarded at 302 medal ceremonies.
The show also included a performance of David Bowie's song "Heroes" by British rock group The Feeling and a typically bombastic speech by London Mayor Boris Johnson.
In a quirky twist, the Olympic countdown clock in Trafalgar Square read 366 days to go. No, it wasn't a glitch — 2012 is a leap year.
Earlier Wednesday, the $442-million swimming complex was officially opened, the last of the six main venues in the Olympic Park to be completed. The 80,000-seat main stadium, the velodrome, handball arena, basketball venue and international broadcast center were all finished earlier this year.
In central London, British Prime Minister David Cameron marked the milestone by inspecting preparations for a beach volleyball test event at Horse Guards Parade next to his Downing Street home.
A year from now, London will be welcoming 10,500 athletes from more than 200 countries, 5,000 coaches and team officials, 20,000 media personnel and hundreds of thousands of visitors. The 17-day festival will feature athletes competing in 26 sports in 32 venues.
Ninety percent of the venue construction is complete, a record number of tickets have been sold and organizers remain within the $15 billion budget.
"London is extremely well prepared," Rogge said. "I'm a happy man. I'm very optimistic for the remaining year to come. I think we'll have great games."
He said London is among the best prepared host cities a year out from the games.
"I think we can compare the operational readiness we have in London to the one we had in Sydney in 2000 and with Beijing in 2008," he said. "Both games were a great success, so that gives me a lot of optimism that London will be successful."
No one was busier Wednesday than London organizing committee chairman and former two-time Olympic 1,500-meter champion Sebastian Coe, who shuttled from event to event and spoke in countless interviews.
"It's enchanting," Coe told The Associated Press as he hustled through the swimming venue. "It really is. I'm just pinching myself that we are where we are."
Early in the day, Coe and Olympics Minister Hugh Robertson took off their shoes and socks to have their footprints cast in clay at St. Pancras station, where the Eurostar train will be bringing in thousands of passengers next year from Paris and Brussels.
Rogge was impressed when he visited the aquatics center, with its signature sweeping wave-shaped roof that measures 525 feet long and 295 feet wide.
"I had a visual shock when I came in," Rogge said. "I've seen many great venues in my life, but this is something really special — the harmony, the quality, the innovation. Really, it's a masterpiece."
The complex, designed by renowned architect Zaha Hadid, seats 17,500 for the Olympics — the second highest capacity of any of the games venues. A year from now, Michael Phelps, Ian Thorpe and Ryan Lochte will be among those competing for gold medals in the pool.
"The water looks good enough to drink," Johnson, the London Mayor, quipped.
Two giant wings of temporary seating have been added to accommodate fans, but will be dismantled after the Olympics to leave a 2,500-seat venue. The high, steeped banks of seats will leave some Olympics fans with a distant view of the action.
Rogge and London organizers posed with Olympic mascot Wenlock next to the pool as local swimmers did a few laps and British synchronized swimmers performed a routine to the strains of Queen's "We Will Rock You."
AP Sports Writers Rob Harris and Caroline Cheese contributed to this report.
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