PHOTO: The large pit will take five years to fill.

It will take five years and cost $100 million to fill an enormous quarry pit in Melbourne’s outer east before up to 1000 houses are built on top of it.

The 25-hectare pit at the historic Cave Hill quarry in Lilydale, formerly owned by Dame Nellie Melba’s family, was operational for 137 years before it closed in 2015.

It is part of the sprawling 163-hectare site, bordering Mooroolbark Road and Lillydale Lake, slated to become a $2 billion residential and mixed-use precinct housing 8000 residents.