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. research structures
9. research buildings

Anotations

Scope note:

Built works that measured the water level of the Nile River during the flood season, either by markings on walls of stepped structures, or on vertical columns erected in the river itself or in specially built cisterns. Originated in Ancient Egypt and used until the Aswan dam was built.