Part of Britain's only known Roman chariot racing track is up for sale.
Now a national appeal is being launched to raise the money to buy it.
House builders Taylor Wimpey have offered a Colchester-based community consortium six months to raise the funds to buy the Victorian built Sergeants’ Mess.
And it includes in its front garden the site of all eight of the circus’s starting gates.
The consortium is trying to put together a financial package to raise the funds which would depend on one or more private buyers purchasing one half of the building.
The other half would be used as a visitor centre for the circus and a permanent base for the Colchester Archaeological Trust.
Philip Crummy, director of the Trust, said the recession and the freeze on housebuilding had offered a window of opportunity which they were trying to take.