Four-cavity well is also known as "Four-eyed well " or "Four-hole well ", situated north-end of the Jhongyang Street in Magong, which is also locally known as the "Upper Street ". There is no precise document regarding when the Four-eyed Well was dug, but judging by the fact that the Jhongyang Street is one of the oldest streets in Penghu, this well was probably dug in the Yuan Dynasty, when the "Lower Street " villages were densely populated and moved to "Upper Street ". Since people cannot live one day without water, when ancestors reached the "Upper Street ", they must have dug this well first as a source for water and for public use.

This Four-eyed Well is about three meters deep and two meters in diameter. There is a stone slate covering the well opening, leaving four circular openings to retrieve water, such peculiar design structure is what gave it its name. According to legend, the Four-eyed well remained running even during draughts, and the water is clear and cool. However, since the establishment of tap water plumbing, this has been turned into a well for washing only.