The Pyramids of Güímar are six rectangular pyramid-shaped, terraced structures built from lava stone without the use of mortar. They are located in the district of Chacona, part of the town of Güímar on the island of Tenerife in the Canary Islands, Spain. The structures have been dated to the 19th century AD and they may originally have been a byproduct of contemporary agricultural techniques. These pyramids stand as high as 12m. Other pyramids employing the same methods and materials of construction can be found in various sites on Tenerife. In Güímar itself there were nine pyramids, only six of which survive. Research history Thor Heyerdahl's hypothesis In 1990, adventurer and publisher, Thor Heyerdahl, became aware of the "Canarian Pyramids" by reading an article written by Francisco Padrón in the Tenerife newspaper "Diario de Avisos" detailing "real pyramids on the Canaries". As Heyerdahl had hypothesized a transatlantic link between Egypt and Central America, he became intrigued by the Güímar pyramids and relocated to Tenerife. There Heyerdahl researched possible parallels between the Canarian terrace structures and pyramid structures in Egypt and Central America in pre-Columbian Mesoamerica as ceremonial areas. Heyerdahl hypothesised that the Canarian pyramids formed a temporal and geographic stopping point on voyages between ancient Egypt and the Maya civilization, initiating a controversy in which historians, esoterics, archaeologists, astronomers, and those with a general interest in history took part.<ref>Juan Francisco Navarro Mederos: Arqueología de las Islas Canarias", in: Espacio, Tiempo y Forma, Serie I, Prehistoria y Arqueología, Bd. 10, 1997, S. 467.</ref> Astronomical research and Freemasonry In 1991, research by Juan Antonio Belmonte Avilés, Antonio Aparicio Juan and César Esteban López, researchers of the Canary Institute of Astrophysics, shown that the long sides of some of the terrace structures at Güímar marked the direction of both solstices. The main limiting wall points to the sunset in the Summer solstice and the pyramids have stairs on their western side which face the direction of the rising sun on the Winter solstice. Also, standing on the platform of the largest pyramid on the day of the Summer solstice it is possible to experience a double sunset, as first the sun sets behind a mountain top, then it emerges again from behind the mountain and sets a second time behind a neighbouring peak. However, considering the room for interpretation, it is impossible based solely on these observations to conclude what was the intention