The biggest security operation in the troubled history of Northern Ireland swung into action for the start of the G8 summit and US President Barack Obama's speech in Belfast.
Hundreds of police 4x4s lined the streets of Belfast, while a police helicopter buzzed overhead as Obama addressed an audience of young people shortly after his Air Force One jet landed.
Roads into and out of the city were closed to facilitate the president's visit.
But Obama was not driven to the summit deep in the Northern Ireland countryside, instead catching the presidential helicopter from Belfast to Lough Erne, an exclusive golf resort fringed by lakes 80 miles (130 kilometres) to the south.
British Prime Minister David Cameron, the summit host, arrived on yesterday, and other leaders were flying into Belfast before catching helicopters to Lough Erne.
More than 8,000 police officers have been deployed to the British province for the two days of talks to guard the leaders and stave off anti-capitalist and anti-globalisation protests.
Three surveillance drones will also be employed in the skies over the summit venue.
On the drive from Belfast through the lush Northern Ireland countryside, armoured police Land Rovers could be seen positioned every few miles, with heavily armed police inside.
The security was reminiscent of the darkest days of Northern Ireland, but Cameron has said he chose the location to show off the progress the province has made since it has emerged from three decades of bombings, killings and riots.
"Frankly, ten years ago, 20 years ago, it would have been unthinkable to hold a G8 in Northern Ireland in County Fermanagh," he said.
Hundreds of journalists from around the world covering the talks are based at a media centre on the edge of the town of Enniskillen, six miles away from the Lough Erne resort.
At the resort, an imposing security fence has been erected around the venue, a collection of whitewashed cottages fringed by lakes which are patrolled by police boats.
Campaigners launched two longboats flying sails emblazoned with the slogan "End Tax Dodging", a reference to Cameron's aim to make progress on cracking down on tax evasion during the talks.
It was a rare show of protest -- police have admitted that far fewer demonstrators than expected have made their way to the venue.
