Well, what a good
Why locals love it
It was believed that the water spirits hold a grudge for Tallinn and that they wish the destruction of the city by an apocalyptic flood. Cat's Well was seen as a potential instrument of destruction at the hands of the water spirits. So it was decided that the way to appease the spirits and prevent flooding was by throwing dead cats into the well.
Why you should visit it
You can peek at how a city well could have looked like in the early medieval times. And marvel at the stupidity of Medieval Estonians. The well was eventually closed due to contamination. Can't think why.
It's a well known place where you can order a taxi in the Old Town. But call it like Estonians - Rataskaevu.