South America – Sechin Bajo (3500 BCE)
A rather recent addition to the list, the oldest building in the Peruvian ruins of Sechin Bajo were only discovered in 2008 by a German-Peruvian archaeological team in the form of a circular plaza measuring 10-14 m (33-39 ft) in diameter built out of rocks and adobe bricks. The discovery pushed the documented age of the ancient city back another 2 500 years and made Sechin Bajo the oldest known urban centre in the Americas. Located just outside of the city of Casma in the region of Ancash about one-third of the way down Peru’s Pacific coast, Sechin Bajo is just one of numerous archaeological sites in the Sechin Valley, which has been continuously occupied ever since as successive cultures built on top of the ruins.
Europe – Cairn of Barnenez (4850 BCE)
The front of the Cairn de Barnenez. Source: NewPapillon, http://commons.wikimedia.org/wiki/File:Barnenez_front2.jpg. Licensed under the Creative Commons Attribution-Share Alike 3.0 Unported licence.
We reach the end of our list of the oldest buildings by continent with the oldest known extant building on the planet, the Cairn de Barnenez on the north coast of Brittany. A giant mausoleum constructed in two separate phases (4850-4500 BCE and 4200-3900 BCE) out of 13-14 000 tonnes of stone, Barnenez measures 72 m (236 ft) long, 25 m (82 ft) wide, and 8 m (26 ft) high. Inside the mound are 11 passages, or caverns, framed with megaliths (large stones), along with numerous internal walls that help to hold the mound up. Many of the passages are lined with carvings and drawings, and pottery shards, stone axes, and arrowheads have been found in the newer section of the mound.
Inside one of Barnenez’s chambers. In comparison to the smaller stones used to build the giant mound, the internal chambers are held up by much larger stones. Source: New Papillon, http://commons.wikimedia.org/wiki/File:Barnenez_entrance.jpg. Licensed under the Creative Commons Attribution-Share Alike 3.0 Unported licence.
The mound was first revealed to be manmade in 1850. Considering that the cairn was regularly used by local as a cheap substitute for a quarry (the stones made particularly suitable paving stones and even after the human origin of the cairn was revealed, stones were being stripped away by locals as recently as the 1950s), it’s amazing that Barnenez has persisted this long. It was only when enough stones had been stripped away to reveal the internal chambers that the populace realised that the great mound of rocks was something special. Excavation and restoration work was carried out on the cairn between 1955 and 1958, and Barnenez has remained in public hands ever since. The site is now a interpretative centre and is open to tourists year-round.
Centre des monuments nationaux (2013). Cairn de Barnenez. Available at http://barnenez.monuments-nationaux.fr/en/bdd/pdf/1. Accessed 18 July 2013.
McDonnell, P.J. (2008). Plaza in Peru may be the Americas’ oldest urban site. Los Angeles Times, 26 February 2008. Available at http://gogeometry.com/incas/sechin_bajo_circular_structure_oldest.htm. Accessed 18 July 2013.
Pozorski, S. and T. Pozorski (1987). Early Settlement and Subsistence in the Casma Valley, Peru. Iowa City, IA: University of Iowa Press. Available at http://muse.jhu.edu/books/9781587291944. Accessed 18 July 2013.