Numerous busts are placed along the avenues of the Pincio, originally wanted during the Roman Republic but whose placement began only in 1851 by decision of Pius IX. The number of busts increased over time, and at the end of the sixties the busts were 228 , periodically afflicted by attacks of vandalism which preferably mutilate their noses; there are only three women deemed worthy of a bust: Vittoria Colonna, Santa Caterina da Siena and Grazia Deledda.
One of these busts has an interesting history: in 1860 it was placed at the Pincio, near the Casina Valadier, the "aim" of the astronomical observatory of the Roman College for the determination of the meridian of Rome, at the request of its director, the Jesuit astronomer Angelo Secchi. It was originally just a checkered wooden tablet which was then rebuilt in marble and set on a column with a hole that allowed it to be illuminated at night. In 1878, on Secchi's death, his bust was placed on the column and surrounded by a small garden . Damaged in 1960, it was restored in 2001 and still provides aiming (although no longer needed).
In picture: Marco Polo, traveller, Republic of Venice 1254 - 8 January 1324 (aged 69–70) (https://en.wikipedia.org/wiki/Marco_Polo)