Mermaid reports from the 1400s
1 case, best-documented first. Page 1 of 1.
We map claims, not creatures. A case is what some source says someone saw or heard, with the link to that source. It is not proof that anything was there, and a retelling counts once, not as a second sighting.

Mermaid · Netherlands · 1403
A mermaid taken in a lake in Holland in 1403 was carried into the city of Haelem where she lived for many years.