Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Built Environment (hierarchy name)
4. Single Built Works (hierarchy name)
5. single built works (built environment)
6. [single built works by specific type]
7. [single built works by function]
8. fortifications (built environment)
9. forts

Anotations

Scope note:

Fortifications that incorporate enclosed earthworks with bastions (projecting portions) at the angles where the curtain walls meet. They are designed to provide coverage by defensive weapons, which are able to fire from the projecting portions along the fronts of the curtain walls.