More than 30,000 people could descend on a Tyrone town on July 12 with a major Orange parade and crucial GAA game set to take place.
Omagh will host one of the main Twelfth demonstrations on the same day that an All-Ireland qualifier may be staged.
Whether the GAA will be sharing the town with the Orange Order all depends on the outcome of the replay of the Ulster Championship semi-final between Armagh and Monaghan this Sunday.
The losers have been drawn against Tyrone in the All-Ireland qualifiers. If it is Armagh, it is expected that the Orchard County will take on the Red Hand County at Healy Park in Omagh on Saturday, July 12.
But if it is the Farney men, then the match is expected to take place at Clones in a repeat of this year's first round clash between the sides.
It's estimated a Tyrone v Armagh clash would bring around 20,000 GAA fans to Omagh on the same day that 5,000 Orangemen and thousands of supporters will be celebrating the Twelfth, presenting a potential logistical and traffic nightmare for police.
The main Orange parade will take place earlier in the day. However, the return parade will leave the field at 4pm, shortly before the throw-in at Healy Park around teatime.
This year will be the first time that Omagh has hosted a major Twelfth demonstration since 2008.
Omagh District LOL No 11 will be joined by representatives of up to 60 west Tyrone lodges from Sixmilecross, Fintona, Newtownstewart, Killen and Strabane.
The parade will start and finish at Campsie Playing Fields.
The playing fields are around four miles from Healy Park.
Local Ulster Unionist councillor Chris Smyth said as well as congestion, he was concerned at the "possibility of trouble".
He is not a member of the Orange Order, but said he planned to be in the town to watch the parade.
"The situation presents the possibility for trouble. If there is trouble on the Twelfth it will put us back," he said.
"The Orange Order have worked very hard to make the Twelfth an inclusive event, and it should be an event open to everyone.
"However, I am worried about the possibility for trouble here."