No doubt travertine is the stone of Rome.

colosseum

Colosseum

colonnade

Colonnade

fontana-del-tritone1

Fontana del Tritone

Bernini used it also for sculptures (Fontana del Tritone).

burghausen-castle01

Burghausen Castle, Europe’s longest castle, is 1,000 years old and built mainly with travertine.

azadi-tower

Travertine and Joshaghan for AZADI Tower