The wreckers struck on three separate occasions over the weekend, smashing windows on the building - less than 12 months after it had been refurbished.
The attacks were spread over Friday, Saturday and Sunday nights.
South Ribble Police are investigating with forensic teams analysing footprints and blood swabs taken from the scene. South Ribble Council meanwhile is studying CCTV evidence from the three nights.
Councillor Paul Foster, counci leader, said: “This is bitterly disappointing news, just terrible. We spent £200,000 in 2019, renovating Worden Park Conservatory, only for this to happen.
Driver caught 'snoring merrily away' on the M6 near Bamber Bridge with full-beam headlights and engine running
Fulwood flasher wearing balaclava leaves mum and her seven-year-old daughter feeling 'shaken up'
M6 to close overnight to allow two bridges damaged by vehicle strikes to be repaired
Murder inquiry launched after man critically injured in Preston assault dies
Leyland residents claim they are paying grounds maintenance fees to make it look "worse"
“I can’t tell you how devastated we are. Myself, fellow councillors, the Friends of Worden Park, and the council’s neighbourhood officers who work in Worden Park every day are all just flabbergasted that someone would even think to do this.
“I would like to thank the duty officers who patrol the park at weekends for their response and for how calmly and professionally they have handled, and continue to handle, the incident.
“We are reviewing the CCTV footage we have, and the police are looking at the evidence they have built up, so hopefully we can get to the bottom of this.
“I would urge anyone with information about this to call the police on 101.”
The 2019 renovation of the conservatory was a difficult, lengthy process but essential towards maintaining the park’s rich history and heritage.
The conservatory – built in 1892 – has always been a hugely popular. Most recently it was used to cultivate plants for the award-winning park, many of which are now ruined.
The attacks, highlighted on the Leyland Memories public Facebook group, outraged folk.
Mike Bell said: “My mum’s ashes are scattered in front of that greenhouse, she used to love sitting there while out with her dogs.”
Ann Christopher said: “Disgraceful acts of vandalism,they should be ashamed of themselves.”
Barbara Wiggins posted: “Do the vandals not know we all pay rates including the vandals’ parents so we can have a nice park and greenhouse. All the glass that has to be replaced will come out of South Ribble Council who we all pay rates to.”
Anyone with information is urged to ring police on 101.