Many of the features of Vicino’s garden were based, through archaelogical and literary investigation, on ancient Roman models. This was certainly the case with the Hippodrome garden - a large, race-track shaped garden that Vicino based on those common in Roman villas. Those entering the garden, if sufficiently iconographically trained, are warned of a potential threat by the presence of large pinecones and acorns decorating the perimeter. Acorns emblematise the Golden Age, pinecones death, making the Hippodrome a false paradise for unprepared visitors. Such a threat becomes more pressing in the form of three female figures who roam the Hippodrome; one with bifurcated fish-tails, one with a dragon’s tail, claws and wings, the other surmounting a bench on which only the most foolhardy would sit. These Harpies, according to Darnall and Weil (1984), make another connection with Orlando Furioso, the episode where the King of Ethiopa, Prester John, is rescued from harpies by the hero Astolfo, who drives the harpies into the mouth of hell using magic. Bury (1985) contests the identification of the fish-tailed figure as a Harpy, pointing out, rather sensibly, that she is more likely to be a Mermaid.
Also in the Hippodrome can be found part (the socle) of a copy (according to Darnall and Weil) of the Meta Sudans, an ancient fountain that once stood in Rome between the Colosseum and the Arch of Constantine. The inscripition carried on this base reinforces the idea that the Hippodrome represents a terrestrial paradise:
CEDAN ET MEMPHI ET OGNI ALTRA MARAVIGLIA / CH HEBBE GIA IL MONDO AL PREGIO AL SACRO BOSCO / CHE SOL SE STESSO E NVLL ALTRO SOMIGLIA
(Memphis and every other marvel that the world has held in praise yield to the Sacro Bosco that resembles itself and nothing else)