Here, where the breezes could tame the Roman summer, he had the Florentine architect Antonio del Pollaiuolo, design and complete by 1487 a little summerhouse, which also had views to the east of central Rome and north to the pastures beyond the Castel Sant'Angelo (the Prati di Castello).

[1] When Pope Julius II came to the throne in 1503, he moved his growing collection of Roman sculpture here, to an enclosed courtyard within the Villa Belvedere itself.

Bramante's design is commemorated in a fresco at the Castel Sant'Angelo; he regularized the slope as a set of terraces, linked by rigorously symmetrical stairs on the central longitudinal axis, to create a sequence of formal spaces that was unparalleled in Europe, both in its scale and in its architectural unity.

[2] The divided stair to the uppermost terrace, with flights running on either side against the retaining wall to a landing and returning towards the center, was another innovation by Bramante.

He completed his structure with an uppermost loggia that repeated the hemicycle of the niche and took its cue from scholarly reconstructions of the ancient sanctuary dedicated to Fortuna Primigenia at Praeneste, south of Rome.

James Ackerman has suggested that the move was a conscious one, designed to screen the secular, even pagan nature of the Cortile and the collection of sculptures that Pope Adrian VI had referred to as "idols".

Today the lowest terrace is still called the Cortile del Belvedere, but the separated upper terrace is called the Cortile della Pigna after the Pigna, a large bronze pinecone, mounted in the niccione, likely to have been the finial of Hadrian's tomb or, as supposed in the Middle Ages, to mark the turning point for chariots in the hippodrome where many Christians were martyred.