Greencastle Hill, Antigua — A Tropical Stonehenge?

Maura Imbert visits a hillsite in Antigua which could be an ancient temple and observatory

  • Track leading to megaliths. Map adapted by Winston Cumberbatch
  • An isolated megalith stands guard. Photograph by Simon Lee
  • Placement of rocks on Greencastle Hill. Photograph by Simon Lee

Once upon a time I was an ardent rock-climber with my eyes on the Matterhorn. So when I started married life in Antigua, one of the flattest islands in the Caribbean, I wanted to climb whatever was available. That is how I found myself, in the late 50s, climbing Greencastle Hill with a small group of enthusiasts led by the late Charlesworth Ross, who believed that the hill was an ancient temple or an astronomical site.

All it takes is a gentle saunter to reach the top of Greencastle Hill, Antigua’s “tropical Stonehenge”. Though it was over 40 years ago, I remember Charlesworth Ross hacking his way through the bush towards the megaliths, which stood about 100 metres above sea level.

In 1926, when he was still a schoolboy, Ross had been introduced to the site by William Forrest, who believed that the hill was an astronomical observatory. Forrest sent photographs and a sketch map of the site to Ludovic Mann, once chairman of the Glasgow Archeological Society, who said it was “a prehistoric astronomical outlay for the purpose of recording time.” Mann also thought that the stones grouped on the site resembled the principal stars in the southern constellation of Sagittarius.

As with many megalithic sites around the world, Greencastle Hill has provoked considerable controversy and debate. Some historians, including Fred Olson, who uncovered remarkable Arawak artefacts at the site, believed that the megaliths were natural formations. But wherever controversy like this exists, it is logical to take astronomical measurements of solar, lunar or stellar alignments with the megaliths; a degree of healthy scepticism should be maintained, since certain alignments can be coincidental or accidental.

The island of Antigua subsided at the beginning of the Oligocene period, about 38 million years ago, and its volcanic base was exposed to the sea. Wave action reduced its girth and formed cliffs on its south-west face, in which an ancient vent, filled with huge boulders, was uncovered. Subsequent erosion produced a plateau strewn with boulders of many shapes and sizes. Unlike Stonehenge, that famous megalithic site in England, where builders had to transport huge boulders over great distances to the site, the ancient priests/astronomers on Greencastle Hill (if they existed) had abundant megalithic material readily available.

Certain features are common to all reputed megalithic sites, including Stonehenge, Tenabo in New Mexico, and Greencastle Hill. They include circles of stones or boulders, and horseshoe-shaped formations. In his book From an Antiguan’s Notebook, Charlesworth Ross, an enthusiastic believer in the astronomical significance of Greencastle Hill, described the west and south flanks of the hill as “steep with numerous megaliths, many forming circles and semicircles.” He also mentioned a large group of megaliths situated near the west end of the central elevation. These he considered to be the sites of a temple and an observatory. The megaliths are arranged in the form of a horseshoe.

Circular and horseshoe-shaped stone groups are found at Tenabo and at Stonehenge, which is widely (but not universally) believed to be an ancient astronomical observatory.

Stonehenge consists of concentric circles of megaliths. The innermost formation is in the shape of a horseshoe, flanked by five huge trilithons, also in the shape of a horseshoe. The first archeo-astronomical determinations were made in 1740 by William Stukley, who found that the principal axis of the site was oriented in the direction of the rising sun during the summer solstice. Subsequent determinations of solar, lunar and stellar alignments have been made.

Various bearings taken at Tenabo, to determine whether there is any alignment with the rising and setting of various celestial objects, produced a number of positive correlations; it is thought that the Pueblo Indians of the area could have used the site as an astronomical observatory. The investigators found it highly unlikely that the results could all be due to chance alignment, even though some of the correlations were dismissed as spurious.

Similar determinations have not, to date, been carried out at Greencastle Hill, though rumour has it that a survey is planned, and there is considerable interest among archeologists.

How Charlesworth Ross would have enjoyed being part of this Antiguan project! I can still see the excitement radiating from him as he pointed out a broad vertical megalith, two metres high, with a horned symbol on the upper margin, representing the Moon Goddess. He thought that several recumbent slabs lying near this megalith may have been used for sacrifices. He pointed out a near-inconspicuous landmark on the north-west margin of a large circular plateau which was higher than the main group of megaliths, and which cut through solid rock in places; it was found to be aligned with the main axis of Greencastle Hill. He considered the possibility that other landmarks on the plateau could be astronomical records. I remember climbing up to an imposing group of megaliths on a higher plateau, where an isolated tapering megalith, about three metres high, was surrounded by a circle of boulders. To Ross, this megalith represented the Sun God.

Historian Desmond Nicholson has pointed out that, with so many rocks and boulders on the site, it is not surprising that some seem to stand vertically or form circles. He admits, however, that this does not prove that they have not been moved, or preclude the possibility that the prehistoric people of Antigua did not use Greencastle Hill as a place of worship.

I have heard that there are plans for extensive quarrying operations east of the site. Hopefully, the proposed archeo-astronomical investigation will take place before this gets under way.

Thanks to local historian Desmond Nicholson and agronomist/amateur astronomer Brian Cooper.

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