Criptoportico della Biblioteca Coccanari Fornari

The cryptoporticus beneath Tivoli's Biblioteca Coccanari Fornari preserves a late-Republican Roman structure within a later civic building. Two parallel vaulted spaces and an older pavement reveal successive phases beneath the historic centre.

Why it matters

The remains show how Roman builders used covered substructures to support development on sloping ground. Their survival beneath a palace and library adds an archaeological layer to the later urban fabric.

What to notice

Local limestone forms the net-patterned opus reticulatum walls. A central wall separates two parallel spaces beneath barrel vaults, with splayed window openings. A surviving area of earlier cocciopesto flooring is decorated with a diamond-shaped grid of white tesserae. The contrast between walling and pavement makes the sequence of construction particularly clear.

Context and history

The cryptoporticus dates to the second half of the first century BC and was probably intended to extend and support buildings above it. Excavation revealed that it rested on earlier structures, including the pavement dated to the second or first century BC. The later Coccanari Fornari palace and municipal library introduced further uses above the ancient remains.