Watch: suspended swimmers cool off in London's 'sky pool'

Transparent structure stands 35 metres in the air and connects two luxury apartments

Is it a bird? is it a plane? No, it's someone swimming in London's 'sky pool' as the UK enjoyed its warmest day of the year on bank holiday Monday.

This seemingly implausible sight became a reality in April when a world-first swimming pool opened in the UK capital, albeit only to residents of the luxury £1 billion ($1.42bn) Embassy Gardens development,

The 25-metre acrylic aquarium-style pool was made in the state of Colorado in the US and carried more than 8,000 kilometres to the Nine Elms district in south-west London.

Connecting the 10th floors of two apartments at Embassy Gardens, a few lengths of Sky Pool provide exercise and a panoramic view of a score of world-famous landmarks.

Sky Pool swam from the boundary-pushing mind of property developer Sean Mulryan and was built by EcoWorld Ballymore.

Scroll through the gallery below for pictures from launch day and more information on the vertiginous project.

Sky Pool gallery

The transparent pool sits on the Sky Deck of the Embassy Gardens development in south-west London. Adjacent to the US embassy, it stands 35 metres in the air. AFP

The world-first 25-metre-long Sky Pool allows residents to swim from one building to the other, 10 storeys above the ground. AFP

Models under azure skies swim in the Sky Pool to mark its opening on Friday. AFP

Property developer Ballymore calls it 'the perfect escape from the busy London life'. AFP

'There’s never been something transparent spanning two buildings like this. Once you swim off, you can look right down. It will be like flying,' said Eckersley O’Callaghan structural engineer Brian Eckersley.

Before Embassy Gardens was built in the Nine Elms district, the locale was considered to have no purpose. Getty

The 'Sky Pool' wasn't the limit for the Nine Elms regeneration project - it also created 25,000 new jobs, a gym, a cinema and private lounges galore. Getty

More on architecture

Megaprojects: 10 tallest buildings in the Middle East – in pictures