The Bass Rock is an island located in Firth of Forth in the east of Scotland. The Bass Rock is currently uninhabited, however at one time is was the site of a royal castle, often used as a prison. In fact, some pretty infamous people had the pleasure of spending a few nights on this volcanic plug of phonolite due to the orders of James I during the 15th century.
I think what really intrigues me the most about this area was the fact that the castle, although the island is quite amazing in the background, was entirely built of rubble and the local basalt. Every part of the castle was dated in such a sporadic way, which leads me to believe that this structure went through an evolution of sorts of war and the turning of hands.
I know when we speak about medieval castles that the construction materials included timber, local stone, mortar, or any other material that were available. I just find it so fascinating that they used the basalt, possibly from the eruptions beneath Bass Rock Island, to construct the castle.
So why is this so fascinating to me? I want to know how old the castle really is. We can all agree that the castle was built around the 16 or 17th century. However, how old is the rock that was used to actually construct the castle?