Jezioro Szmaragdowe (Szczecin)
Jezioro Szmaragdowe is a flooded chalk pit in the Zdroje district of Szczecin, named for the colour that calcium carbonate and the chalk bottom give the water. Per search summaries it is about 4.5 ha and up to 18 m deep with a section of rail track, a wagon and flooded trees on the bottom. Visibility is reported as usually poor, below 4 m, and the calcium-rich water holds little life.
depth: 0–18 m