Sprawling over 20 acres, the elaborate maze is oriented so that the sun sets behind particular standing stones on the days of the equinoxes and the summer and winter solstices. Some scholars believe the stone complex might have been used for bloody religious rituals. A huge, bell-shaped stone in the center of the complex does, in fact, resemble a sacrificial altar. In the 1930s, one popular explanation was that a group of shipwrecked Irish monks had built Mystery Hill hundreds of years ago. In 1967, radiocarbon tests indicated that Mystery Hill might be at least 4,000 years old.
Most mainstream archaeologists take a differ view.
According to Bob Goodby, president of the New Hampshire Archaeological Society, there is nothing mysterious about Mystery Hill.