A recently refurbished playground was covered in glue in the second vandalism attack this summer.
PVA glue was found smeared over equipment at Evans Road Playground in Neath over the weekend.
The park was completed at the end of May this year, after receiving a £42,000 refurbishment.
Shortly before it was due to be signed off for use this summer, somebody burned play equipment at the park with a lighter.
Now it has been attacked a second time.
Councillors and residents have expressed their dismay at the incidents.
Neath East Councillor Sandra Miller said all three Neath East councillors put £10,000 each towards the refurbishment in a long anticipated improvement to the facilities.
She said: "The aim was to get the park completed by the summer holidays ready for the children to play in and to give parents a chance to speak to each other.
"It was sickening for me. We tried our best to make it better for people. If this has happened already, what's going to happen next?"
Councillor Miller also said that, although PVA glue could be easily removed with chemicals or warm water, it was disappointing that somebody would want to cause damage to the park or to inconvenience the children.
She warned: "With the school holidays advancing, parents will now need to be vigilant about damage that could harm their children."
More about vandalism:
Neath Port Talbot Council staff have since removed the glue and said they would "order the damaged parts".
