Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Monastery of Batalha' has mentioned 'Octagon' in the following places:
Occurrence Sentence Text Source
The chapel consists of three notional bays and a central octagon buttressed by eight piers, adorned with crockets, supporting deeply stilted arches.
The joint tomb of King John I of Portugal (d.1433) and his wife Philippa of Lancaster (d.1415) stands under the star vault of the octagon.
This octagon is surrounded by an ambulatory with complex vaulting.