The Hamtoren is the remains of the historical Den Ham Castle in Vleuten. The tower is located north of the Utrecht–Rotterdam railway line, on an old road connecting Harmelen and Utrecht.
Wikipedia https://en.wikipedia.org/wiki/Hamtoren
Address 3 Hamlaan, 3451RG, Netherlands
Coordinates 52°6'21.099" N 4°59'43.704" E