This crusher is found at Capernaum, Jesus' home-base (Matthew 4:13), near the synagogue. The local basalt "a hard, volcanic black rock" made excellent crushers and other types of grinders.
Jesus frequently saw crushers and millstones like this one. The basalt grinders are found in archaeological remains around the country. They were probably exported from the area of the Sea of Galilee. Jesus' teaching about being a proper influence on "little ones" or facing a fate worse than being thrown into the sea (the Sea of Galilee is barely 100 feet to the left) took place here (Matthew 18:6).