The Disturbing Abacus of Alda Horizon is a 2416 years old piece made by Alda Horizon, a merchant living in Lisbon.
Considering its age and the quality of the work, people consider it of considerable value.
It is engraved with european patterns and some symbols pertaining to Folk religion.
This piece doesn't exist, but as a legend. It is said that in the year 1536, Alda Horizon, the owner, made use of it in Lisbon to empower the Horizon family. Now it is lost, or broken, we will never know.