Leicestershire County Council has confirmed Snibston Discovery Museum will close as part of ongoing cut backs.
The local authority needs to save £120 million over the next year.
The Science and Technology attraction has annual running costs of £900,000.
A smaller mining museum is planned to replace Snibston, which would save the council £0.5 million a year.
Snibston Discovery Park in Coalville is celebrating its 21st anniversary by turning back ticket prices to 1992 rates.
Located on the site of the former Snibston Colliery created by famous railway pioneer George Stephenson, Snibston comprises an interactive museum, historic colliery railway, outside play areas and a Country Park and nature reserve covering over 40 hectares.
For today only, adults will only pay £3 for entry to the park. Children and concessions rates have been dropped to £2.