Gallery: Massive bonfires set to be lit across NI to mark the 11th Night
Huge bonfires are to be lit in loyalist communities across Northern Ireland ahead of the main date in the loyal order parading season - the Twelfth of July.
The traditional "Eleventh Night" fires mark the start of commemorations to mark the victory of the Protestant King William of Orange over Catholic King James II at the Battle of the Boyne in Ireland in 1690.
The towering structures, most built with stacks of wooden pallets, will draw thousands of onlookers, but they are often the source of controversy.
To their defenders they make for a family-friendly, spectacular celebration of loyalist/Protestant culture; to their detractors they are potentially dangerous, environmentally damaging, magnets for anti-social behaviour and alienating to nationalists.
In recent years, bonfire builders have faced criticism after items linked to the nationalist/republican tradition - such as Irish flags and posters and effigies of high-profile politicians - have been placed on the top of some of the fires and torched.
Last year, homes near Chobham Street in east Belfast had to be evacuated over fears the giant nearby bonfire could topple on to property.
While this year's bonfire in that neighbourhood has been moved away from those homes, and is set to be smaller in scale, the fire is still proving contentious.
Equipment in a newly-built children's play park has had to be moved amid fears of damage.
At the Ballybeen bonfire at Dundonald in greater Belfast, environmental concerns about noxious fumes have been raised after footage emerged of a large number of tyres being dumped at the site for burning.
All the fires will be lit late on Monday night, ushering in Tuesday's Twelfth events.
Authorities in Northern Ireland are cautiously optimistic the Twelfth can pass off peacefully, but have a major policing operation planned to deal with any unrest.
While the vast majority of the almost 600 Protestant loyal order parades are free of trouble each year, the threat of disorder at a small number of remaining marching flashpoints always has the potential to mar the day.
Thousands of Police Service of Northern Ireland (PSNI) officers will be deployed to parades across the region on Tuesday, with contingency plans in place to call on additional Mutual Aid support from other UK forces if required.
PSNI commanders are confident such back-up from Great Britain will not be needed this year.
A number of early summer parades that in the past have witnessed trouble have passed off without major incident in 2016.
A deal to resolve the region's most volatile Twelfth parading impasse - at the Ardoyne/Twaddell Avenue community interface in north Belfast - collapsed last month.
However, the breakdown of negotiations between the Orange Order and nationalist residents in the Ardoyne area was not accompanied by the recriminations some might have expected.
The area has been the scene of rioting on a number of previous Twelfths - with republicans and loyalists both having engaged in violence.
Away from the Twaddell dispute, one of the other main areas of concern this year - in the Castlemara estate in Carrickfergus - is actually linked to tensions within loyalist paramilitarism, rather than a parading dispute with nationalists.
Alcohol has undoubtedly been a factor in the disorder witnessed during previous Twelfths.
The Orange Order has been pro-active this year encouraging Orangemen and women, loyalist bands and supporters to stay off the drink with a campaign titled "It's about the battle, not the bottle".
The Order plans to hand out thousands of bottles of water branded with the slogan on the day.
Northern Ireland's First Minister Arlene Foster, Deputy First Minister Martin McGuinness and Justice Minister Claire Sugden have called for a "peaceful, respectful and safe parading season".
In a joint statement on Sunday, they said: "The celebration of different memories, cultures and traditions in a respectful, dignified and peaceful manner has the potential to enrich our society. Equally, some may wish to protest and it is essential this is done in a way that is peaceful and does not undermine law and order.
"As we move into a period which has in the past resulted in heightened tensions, we encourage everyone to conduct themselves in a dignified and lawful way."