Imagine a tiny cave deep inside the ground where there is a hole in the roof. Through this hole, water droplets fall from the sky and slowly make their way down into the cave. As they fall, the water picks up minerals in the ground like calcium and magnesium.
Over time, a little pool of water forms at the bottom of the cave. This water is full of minerals that have dissolved in it from the rocks above. As the water from the pool slowly evaporates, the minerals are left behind and begin to harden. This process is called petrification.
The minerals that are left behind form a hard, stone-like substance that can take on the shape of whatever was in the pool. In the case of a petrifying well, things like twigs, leaves, and even small animals can become petrified.
So, a petrifying well is a special kind of cave where water with special minerals drips into a small pool, evaporates, and leaves behind hard stone-like objects. These objects can be things like twigs and leaves, or even small animals, that become petrified over time.