Ireland
The Emerald Isle
|
IrelandThe Emerald Isle | |
Dùn Aonghasa is the most famous of prehistoric forts built on the Aran island of Inishmore at the edge of a one hundred foot cliff and is thought to have been constructed during the Iron Age in the 2nd Century B.C. by the ancient Celts. Portions of the fort have fallen into the sea and it is believed to have been either oval or D-shaped, depending on my source and the walls up to a width of four meters wide at points. |
|
The Dùn Aonghasa fort is a series of concentric walls of dry stone construction, built with no mortar or cement, and outside the third ring lays a defensive system of upright stone slabs, known as Cheval de fries in medieval times. 
|
|
The photograph below left was taken from a doorway in an outer ring and on the right is a photograph of the innermost wall at the edge of the cliff. 
|
|
The walls were constructed without mortar with a slight downward tilt toward the outside of any rooms to allow rainwater to fall outside and this construction is known as corbel vaulting. 
|
|
This is looking across from inside the second innermost ring to the inner ring of the fort - the buttresses were added much later and not a feature of the ancient Celtic fort. 
|