Most of the instrumental historical heritage is held by the oldest INAF Astronomical Observatories and includes over a thousand pieces: quadrants, telescopes, theodolites, clocks, globes, mathematical and meteorological instruments, ranging from the sixteenth century to the first half of 900.
The instrumental collections were formed from the gathering of Observatory apparatus, bought or purpose-built by skilled mechanics, which having became unsuitable for everyday research, had been set apart.
Some of these collections, now restored, are open to the public and can be visited in the museum space inside their Observatory of origin.