Stepping on to the 'witch-weighing' scales is the main attraction of Oudewater's little Heksenwaag (Witches’ Weighing House), though it's also worth heading upstairs to watch three videos about medieval witch trials, available in English and Dutch and with written explanatory summaries available in a phenomenal 39 languages.
In the inquisition-fearing 16th century, one bizarre 'proof' of witchcraft was that if a woman was 'suspiciously' underweight, it was so that she might take flight on a broomstick. Many innocents went to the pyre because measurement was so notoriously unreliable. However, in Oudewater, the Hekenswaag's set of 1482 scales was said to be infallibly accurate (and those operating it unbribeable) so those under suspicion would attempt to get here and prove themselves too heavy for heresy.