Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Amphitheatre of El Jem' has mentioned 'Stone' in the following places:
Occurrence Sentence Text Source
It is one of the best preserved Roman stone ruins in the world, and is unique in Africa.
The amphitheatre is built of stone blocks, located on a flat ground, and is exceptionally well conserved.
Located in a plain in the centre of Tunisia, this amphitheatre is built entirely of stone blocks, with no foundations and free-standing.