Black Diamond Lake

Black Diamond Lake is a former open-cut coal mine pit lake located near Allanson, about 7 kilometres north of Collie in Western Australia's South West region. Filled with groundwater, it is known for its striking turquoise-blue water contrasting with sandy banks and surrounding bushland. A popular day-use recreation site, it attracts visitors for swimming, kayaking and photography, and is managed as a public reserve within the Shire of Collie.

Visitors can expect a large, vivid turquoise lake set in a former coal mine pit surrounded by sandy banks and open bushland. The site is a day-use area with a gravel car park, basic toilets and picnic tables. There is no built beach or shade structures. Visitors can swim, kayak, stand-up paddleboard and photograph the clear blue water. Banks are sandy and uneven with some steep drop-offs into deep water.