Lost Lagoon was originally a tidal mud flat called Coal Basin and was connected to Coal Harbor. For hundreds of years native people harvested clams from a shell midden that can still be seen on the lagoon's northern shore.
The lagoon was a favorite canoeing spot of native princess and poet E. Pauline Johnson who missed it so much when it disappeared at low tide that she wrote a poem naming it "Lost Lagoon".
In 1916 the construction of the Stanley Park Causeway separated the lagoon from the sea. Salt water was pumped out and replaced with fresh water.
Today the lagoon is a rich habitat for many birds, turtles and other small animals.