Chelsea Football Club has unveiled the first phase of its new multi-million pound training HQ in Surrey.
Owner Roman Abramovich opened the Cobham ground, which has 30 football pitches, a 17m (56ft) hydrotherapy pool and a medical centre.
The club said it had also been designed to fit into its green belt surroundings, with a curved roof planted with growing grasses.
A moat allows light into the basement floor of the three-storey structure.
Because it had been dug into the ground, the HQ was no higher than any of the surrounding buildings.
"Today is a proud day for Chelsea," said chief executive Peter Kenyon.
"We are very near the culmination of many years' hard work to find and build a facility that is key to the future of the club and will be one of the leading centres in the world.
"Developing home-grown players is a vitally important goal for Chelsea.
"Our young players, academy and community coaches will be working closely with the first team - this is very much part of our club philosophy."
The club said the biggest challenge during the two-year construction was not interfering with day-to-day football operations.
The club moved to temporary buildings on the site in January 2005 and work had to be planned round first team training.
Phase two of the development, an overspill academy and community facility, will be completed next year.