VANDALS are thought to have started a spate of fires in the Denaby area of Doncaster, one of which destroyed a building on the old Earth centre site.
The biggest blaze severely damaged a toilet block at the derelict visitor attraction, which has recently been taken over to be converted into an educational activity centre.
Fire crews from Dearne and Maltby stations also found that another fire had been started next to an old accommodation building.
About an hour later they had to return to the Earth Centre when rubbish was found to have been set on fire.
Earlier in the evening firefighters were also called to a separate site on Doncaster Road where two derelict portable buildings were set on fire.
Police are investigating the fires, which may be linked.