Riders have set off on a lap of the region for charity.
The Lap of Anglia left the Queen Elizabeth Hospital at King's Lynn as they began their 400-mile marathon.
The ride is in aid of the East Anglian Air Ambulance, circling its territory clock-wise.
It takes in the north Norfolk coast, heads inland to Norwich, then returns to the coastline to take in Great Yarmouth and Lowestoft.
The route then takes in the Suffolk coast, before Ipswich, Luton, Bedford and Peterborough, before returning to King's Lynn.
It is divided into four legs of just over 100 miles.
Since the first lap in 2013, the event has raised more than £60,000 for the air ambulance.
It aims to raise enough money to keep the helicopter in the air for a day.
Before setting out, riders are warned: 'It will be incredibly tough, give you a sore rear end and burn off quite a few portions of fish and chips.'
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