Janiculum Hill historical timeline

A hill outside the city, used for reading the sky, then for watching the city, then for planting things on.

Chronology

1. Mythological past — in Roman mythology, Janiculum is the name of an ancient town founded by the god Janus, the two-faced god of beginnings. In Book VIII of Virgil's Aeneid, King Evander shows Aeneas the ruins of Saturnia and Janiculum, which Virgil uses to stress the significance of the Capitoline Hill as the religious centre of Rome. Structural impact: none. What you see today: the name.
2. Antiquity — the Janiculum is a centre for the cult of the god Janus, and its position overlooking the city makes it a good place for augurs to observe the auspices. Structural impact: the hill's function is to be looked from. What you see today: the terrace, doing the same job for a different reason.
3. Antiquity, continued — the hill lies west of the Tiber and outside the boundaries of the ancient city, which is why, despite being the second-tallest hill in the contemporary city, it is not counted among the Seven. Structural impact: it stays outside the walls and outside the list. What you see today: the best viewpoint in Rome, omitted from Rome's most famous enumeration.
4. 1520–21 — Giulio Romano builds the Villa Lante al Gianicolo, an important early building by the Mannerist master, also with magnificent views. Structural impact: the hill starts acquiring villas for the view. What you see today: the villa.
5. 16th century — Bramante designs the Tempietto, a small shrine at San Pietro in Montorio marking the supposed site of Peter's death, on what was formerly thought to be the site of Saint Peter's crucifixion. Structural impact: a circular temple in a courtyard. What you see today: it — and its descendants all over Europe.
6. 1514 — Pope Leo X institutes the first chair for the teaching of medicinal plants. Structural impact: none here yet. What you see today: the beginning of the line that ends in the garden on this hill.
7. 17th century — Pope Paul V builds the Baroque Fontana dell'Acqua Paola. Structural impact: a monumental fountain on the hillside road. What you see today: it, filling a wall partway down the slope.
8. 1655–1667 — after the papal residence moves to the Quirinal and the Vatican botanical garden is completely abandoned, Pope Alexander VII Chigi decides to create the new university garden on the Janiculum hill. Structural impact: the hill is designated for botany. What you see today: the reason the Orto Botanico is here and not somewhere flatter.
9. 1883 — after numerous moves, the Orto Botanico finds its definitive location at Villa Corsini alla Lungara, bought by the Italian State from Tommaso Corsini for the Accademia dei Lincei and the garden. The villa already held artistic value through Ferdinando Fuga's restoration, including the fountain of the eleven jets and the fountain of the tritons. Structural impact: a private park becomes a scientific collection. What you see today: the garden's boundary and its two Fuga fountains.
10. 1884–1928 — the first director, Pietro Romualdo Pirotta, creates the entire naturalistic area from scratch, the site having consisted at the beginning only of the ancient wood against the Janiculum and two cedars of Lebanon. Structural impact: twelve hectares of hillside are planted deliberately. What you see today: every tree in the garden except two.

• Official website
• Wikipedia