Twenty-five tonnes of pigeon poo has been discovered inside an ancient monument.
Environmental workers had to wade through around three-feet of "monumental mass of festering faeces" inside the towers of Landgate Arch in Rye, East Sussex.
The build-up of "mushy mess" was so huge that workers struggled to force open the doors to the landmark.
Once inside, workers said it was "like walking on a giant chocolate cake".
"Whilst we’ve removed other massive blockages such giant fatbergs in sewers, we have never seen such a monumental mass of festering faeces before,” Mike Walker, managing director for CountyClean Environmental Services said.
"Once inside, it was like walking on a giant chocolate cake and the smell was awful – even through a facemask.
“The floors of the towers and the steps leading to the top were swamped with 25 tonnes of poo."
Rother District Council, who own the 1340 monument, called in CountyClean amid concerns the acidic piles of pigeon poo could severely damage the ancient stonework and structure of the towers.
Workers used a high pressure tanker to suck up the waste.
"We filled our tanker several times over,” Walker admitted.
Work is due to be completed on Friday.