Sectarian barriers in this segregated and troubled city opened Monday to allow about 3,000 athletes to run in the 4th Annual Belfast City Marathon.
"It is one of the few days in the year when people can mix regardless of their beliefs," said Paddy Murphy of the Northern Ireland Sports Council.
The marathon takes members of the Roman Catholic-minority in the province through Protestant-areas such as Sandy Row, where they could face violence on any other day of the year.
For many Protestants, the race provides a rare glimpse of the Falls Road area, the Catholic ghetto in west Belfast, where the Irish Republican Army draws most of its guerrilla recruits.
"I have met runners from both communities who have seen some parts of Belfast for the first time on the marathon," said John Kinahan, a senior executive for the Guinness brewery.
The winner of this year's marathon was local boy Marty Deane, who finished in a record 2:15:52, while the women's race was won by Moira O'Boyle in 2:45:40, also a record.