Legends and curiosities
from Rodolfo Lanciani [1] - pages 31-32:
A fantasy reconstruction of the island is at Villa d'Este at Tivoli [near Rome], forming part of the relief plant of the city of Rome that Pirro Ligorio planned to add to the curiosities of that delicious place. A water course, derived from the Aniene river, represents the Tiber, in which the ship seems to float, with the obelisk as main tree and the coat of arms of Cardinal Ippolito d'Este as of the emblem of the "merciful God" [1].

from Christoff Neumeister [2] - pages 194-196:
THE INTRODUCTION OF THE CULT OF ESCULAPIO TO ROME (Ovid, Metamorphoseis, XV the 626-744)
The ancient traveller, arriving to the Insula from the Pons Fabricius, would have noticed to his left the sanctuary of the healer god Esculapio = Asclepius. Here is the story.
When on the 293 b.C. Rome was hit by an epidemic that was not possible to wipe out, the Sibillini Books (or the Delphi oracle, according to what Ovid wrote in his Metamorphoses) were interrogated to know how to escape from the flagellum. The answer was to bring to Rome the god Esculapio from its most important sanctuary, located at Epidauro. Therefore an embassy was despatched across the sea, with the task to obtain the god (or better its cult image). However, during the negotiation, suddenly the god itself appeared in shape of a gigantic snake and spontaneously came up to the ship of Romans. They sailed back and, helped by favourable winds, arrived to the Tiber mouths after only one intermediate stop. Here they were received by the jubilant people and when the ship, going back the river, arrived to the city, the divine snake scrambled up on the main tree and watched around; then it slipped down from the ship, taking earth on the Tiberina island, where it was erected a temple.
This is the legendary story that explains because the sanctuary of Esculapio has been founded on the Tiberina island. The true reason should be simpler: in fact it must be considered that, as in other Esculapio cult places, the sanctuary was generally joined to an hospital for which it was suitable an area as much as possible isolated but, at the same time, not too far from the city. The Tiberina island well satisfied both conditions, considering that formerly it was not connected to the city by means of bridges. There were many people that took advantage of the aid of the god (i.e. of its therapists). This is proofed by the inscriptions and mainly the innumerable votive tablets recovered Tiber bed in years 1885-1887, during of the works of rearrangement of the river banks. These tablets were mainly expression of the humbler ranks (liberti and slaves). Since it had been more and more used the cruel practice to forsake on the Tiberina island the sick slaves, whose maintenance had become too much onerous for their masters, the emperor Claudius stated that every forsaken slave, in the case he succeeded in recovering, he could be considered free, without any obligation to come back under the authority of just the master.
In memory of the legend, the island was covered with a travertine layer in a ship shape - but strangely not with the prow against the stream, as it could be expected on the base of the legend, but turned towards the sea as if, let to say, the ship of Esculapio ridded at anchor. The rests of this monumental arrangement are still today visible; in particular the front extremity of the rowlocks zone (see pict.: Reconstruction of the ship prow of Esculapio according to O. Höckmann, München 1985), on whose side these is a ram head shape decoration like that used to protect the ship sides at the mooring; in the front side it is possible to see the famous symbol of the god, than still today is the symbol of doctors and chemists: a stick with a snake twisted around (Ovid, Metamorphoseis, XV 659): serpentem, baculum here nexíbus ambit. On the island it was also symbolically represented the main tree of the ship of Esculapio, from which the snake, at its arrival, saw the place where it would have had to rise its temple: it was an obelisk placed at the center of the island: its foundations were found on 1676.

THE EMBANKMENTS
The destiny of Tiberina island has been in doubt at the end of 1800, after Rome became the capital of Italy. In fact, as often the river broke its banks and flooded the surrounding areas, it was stated to give the Tiber a definitive arrangement in accordance to the new role of the town.
Among the various proposed alternatives (one of them even stating to fill up with earth the left river branch, slower than right one and naturally trending to silt up, with consequent elimination of the island joined to the Tiber left bank) on 1875 it was approved the Canevari project, mainly consisting in restraining the Tiber between two embankments ["muraglioni"], and in particular:
-regulating of watercourse in the urban way to a constant width of 100 m at embankments foot.
-survival of Tiberina island between the left and the right river branches, 60 m and 70 m wide respectively.
-extension of Ponte Cestio and demolition of Ponte Rotto
The works started on 1877.
Luigi Pirandello so described the destiny of the river (from "Pianto del Tevere"):
"You will not see the Tiber anymore as I saw it one day, through Rome running between its natural steps shores. (...) Now a prison of grey dams and heavy bridges embarks the river and strands its winding any time water even more subsides. Dry is the arm which was used to embrace the Two Bridges little island, as though it were its sweet heart."