A defining change
Usable examples of Roman concrete exposed to harsh marine environments have been found to be 2000 years old with little or no wear.
Aha!
Looking closer…
Looking closer…
Move through the dated record of Roman concrete, separating what is documented, what is visible today and what still needs archival evidence.
Usable examples of Roman concrete exposed to harsh marine environments have been found to be 2000 years old with little or no wear.
Aha will show a draggable historical comparison here only when a sourced archival image and a sourced current view are available. Until then, the dated record stays textual and verifiable.
Maps reveal position. Satellite imagery reveals the present landscape. Historical imagery is labeled separately because coverage varies.
Start with the source record behind this Aha.
Inspect evidence ↗mediaBaia-Tempio di Mercurio.jpg · CC BY-SA 4.0
Inspect evidence ↗mediaCaesarea Concrete Bath.jpg · CC BY-SA 3.0
Inspect evidence ↗mediaOpusCaementiciumViaAppiaAntica.jpg · Public domain
Inspect evidence ↗mediaRome-Pantheon-Interieur1.jpg · CC BY 2.5
Inspect evidence ↗Aha distinguishes dated historical records, reusable archival media, present-day maps and satellite context. A historical image is never labeled as ‘Then’ unless a source is attached.