Superheroes will tackle giant inflatable obstacles on a fancy dress assault course to raise cash for charity.
Spiderman and Batman are expected at the Kapow! Superhero Challenge, which will return to the Temple Newsam Estate on June 30.
Last year, more than 1,200 people took part in the event, rising £40,000 for good causes.
It is organised by the Type 1 diabetes charity JDRF, along with other charities.
Sadie Munro, of JDRF, said: “Nine local charities have come on board to help make this event happen,
so we’re set for a super day that will raise thousands for local causes.
"We’re encouraging people to dress up as their favourite superhero too, so whether you are an Avenger, X-Men or Justice League fan all are welcome to take part and be heroes.”
Charities involved in the event include Leeds Cares, the Children's Heart Surgery Fund, Breast Cancer Haven, Leeds Cares, Leeds Mind, RSPCA Leeds & Wakefield Branch, The Encephalitis Society and Leonard Cheshire.
To find out how to enter log on to jdrf.org.uk/kapow