"When viewed from the Heel Stone, a rather enigmatic stone which stands just outside the entrance to Stonehenge, the pits effectively mark the raising and setting of the sun at midsummer days," he explained.
According to the archaeologists, the pits may have contained tall stones, wooden posts or even fires to mark the sun rising and setting. Most likely, they defined a processional route used to celebrate the passage of the sun across the sky at the summer solstice.
"It is possible that processions within the Cursus moved from the eastern pit at sunrise, continuing eastwards along the Cursus and, following the path of the sun overhead, perhaps back to the west, reaching the western pit at sunset to mark the longest day of the year," said Gaffney.
The hypothesis gained more weight when the researchers measured the walking distance between the two pits.
They discovered that the procession would reach exactly halfway at midday, when the sun would be directly on top of Stonehenge.
"This is more than just a coincidence, indicating that the exact length of the Cursus and the positioning of the pits are of significance," said Henry Chapman, senior lecturer in archaeology and visualization at the University of Birmingham.