The discovery was first made in Mexborough’s Pitt Street Park on Tuesday – with the open shaft just yards from a children’s playground.
Concerned residents say the hole on the popular green space – also known as the Rocket - has yet to be repaired – and there are fears someone could be seriously injured or killed unless urgent repairs are carried out.
A dog walker who made the discovery said the 6ft deep shaft was littered with broken chairs as well as broken glass, bottles and cans.
He said: “There’s dogs off the lead that go on that park and kids play on it too.
"Apparently it’s been reported to the council but they’ve not done anything about it.”
“It’s really dangerous isn’t it - on a park of all places. Someone could seriously hurt themselves.”
We have contacted Doncaster Council for comment.