An estimated 110,000 women took part in Race for Life events across the UK to raise money for cancer research, including these runners in Cardiff.
Everyone who took part had the option to walk, jog or run over a distance of 5km. These Belfast entrants are pacing themselves as they go uphill.
Events were held in 16 locations across the UK. Here runners in Belfast pass the newly-restored Northern Ireland Assembly building at Stormont.
In London, 5,000 women took part, with the dome of St Paul's Cathedral looming overhead.
Organisers said that they hoped the runners, including these ones in London, will raise more than £8.5m for research into cancer.
The day's 24 races, such as this one in the UK capital, are part of 280 Race for Life events taking place over the summer of 2007.
Since it was launched in 1994, Race for Life - shown here in Cardiff - has established itself as the UK's largest women-only fundraising event.
Over two million women have run or jogged in Race for Life events since its launch, including these entrants in Edinburgh.
Runners in Edinburgh's Holyrood Park enjoyed the benefit of cooler weather than their counterparts in the south of England.