Lonjé Molen, also known as Tadema's Molen, is a smock mill on the west side of Bolsward, restored to working order. It was originally built as a grain mill rather than a drainage mill, and the surviving milling machinery is intact and operated on open days.
It is one of two surviving Bolsward windmills, the other being De Klaver. Both are best visited together on a walk around the town's outskirts, and both are within easy reach of the centre.