Tiengemeten is an island in the Dutch province of South Holland. It is a part of the municipality of Hoeksche Waard and lies about 11 km south of Spijkenisse. Before 1984 the island was administratively split between Goudswaard and Zuid-Beijerland, and until 2019 it was part of the municipality of Korendijk.
The name Tiengemeten refers to an ancient area measurement; one gemet is comparable with one acre so the name means ten-acre island. Ten gemets would be about 100 by 400 metres, while the island is actually about 7 km long and 2 km wide.
Wikipedia https://en.wikipedia.org/wiki/Tiengemeten
Coordinates 51°44'21.877" N 4°18'25.996" E