Budding designers have just three weeks to submit their entries for Colchester Castle chariot obstacle race.
The Battle of the Ages event, which will celebrate the re-opening of the Castle Park attraction, will see six teams go head to head in knockout races around the bailey.
Schools are being pitted against each other to design the Roman chariot, whilst local community groups can enter designs for the Saxon chariot.
The Iceni, Norman, Cavalier and Roundhead chariots are open to entries from members of the public.
Councillor Tim Young, cabinet member for culture, said: “We are looking for imaginative and fun designs, so whether you create something grand in keeping with Emperor Nero, or a modern take on Boudica’s transport, get your creative juices flowing.”
The closing date for designs is April 25 with winners being announced three days later.
The Battle of the Ages event will run between 11am and 1pm on June 7.
Visit battleoftheages.co.uk for information about each of the eras, key figureheads to use as muses for their designs, and a template on which to submit entries.