Stonehenge is a Neolithic and Bronze Age monument located near Amesbury in the English county of Wiltshire. Constructed between 2500 BC and 2000 BC, it is composed of earthworks surrounding a circular setting of large standing stones, known as megaliths. Archaeoastronomers claim that Stonehenge represents an "ancient observatory," with significant alignments for the sunrise on the solstice and equinox days.