More than £4m ($6.7m, €5m) has been reserved by the Heritage Lottery Fund (HLF) to give a 19th-century lido a whole new lease of life.

After more than three decades of neglect, Cleveland Pools will be returned to its former glory after local activists rallied to secure the monies needed for its restoration.

The Georgian-era facility in Avon has fallen into disrepair since closing to the public in 1978. Once the work is completed, the heritage site will offer a 25m (82ft) swimming pool, children’s pool, coffee shop and pontoon. The original buildings include changing rooms and a supervisor’s cottage.

The outdoor facility is thought to be the oldest surviving public swimming pool in England, and possibly the oldest of its kind in Western Europe. More than the architectural significance, the pools also provide insights into how people lived.

“They have a fantastic story behind them that provides a glimpse into how our ancestors spent their leisure time,” said head of HLF South West, Nerys Watts.

In a statement on the Cleveland Pools website, campaigners thanked the Prince’s Regeneration Trust for advising them on how to secure the HLF grant. “Well, we did it!” the statement said. “We're absolutely over the moon.”

Alongside the community group which has fought to save Cleveland Pools, the project has had the support of a British Olympic medalist – swimmer Sharron Davies – who said she is looking forward to the restoration of a “magnificent and unique pool … for a proper outdoor swim.”