Hagar Qim Interior Apse, Malta
This is part of the well preserved interior apse at Hagar Qim. The blocks are made of globigerina limestone. Follow this link for a layout of the temple’s design.
https://en.wikipedia.org/wiki/Hagar_Qim#mediaviewer/File:Map_of_the_temples_of_Hagar_Qim.tif