Discover Galleria Spada

The Galleria Spada is a state picture gallery inside Palazzo Spada, at Piazza Capo di Ferro 13 in central Rome. It holds the collection assembled by Cardinal Bernardino Spada, displayed in four rooms in the seventeenth-century manner.

Off the courtyard is the gallery's most famous feature: Francesco Borromini's forced-perspective colonnade, built in 1653, with the scientific and mathematical calculations worked out by the Augustinian father Giovanni Maria da Bitonto. The gallery describes a short arcade perceived, through a series of skilful devices, as a long colonnade, with a statue that looms at the far end while in reality being very much smaller. Wikipedia supplies the figures usually quoted: an apparent 37 metres against an actual 8, and a sculpture 60 cm high.

The palace was built in 1540 for Cardinal Girolamo Capodiferro by the architect Bartolomeo Baronino, and bought by Cardinal Spada in 1632. The Italian state acquired it in November 1926 and the gallery opened in 1927.

Open 08.30-19.30, closed Tuesdays; ticket office closes 19.00. EUR 6 full, EUR 2 reduced.

The colonnade is a piece of applied geometry, and it is the reason architects come here. Borromini built it in 1653 and did not do the mathematics alone: the gallery credits the Augustinian father Giovanni Maria da Bitonto with the scientific and mathematical calculations.

The devices all work together. The columns diminish in height along the length; the floor rises; the barrel vault descends; the side walls converge. Each change is small and consistent, so the eye reads the sequence as a long arcade seen in normal perspective rather than a short one deliberately distorted. The gallery's own description is deliberately unnumbered — a short gallery perceived, through a series of skilful devices, as a long colonnade, with a statue that towers in the background while in reality being much reduced in size. Wikipedia supplies the numbers: an apparent 37 metres for an actual 8, and a statue 60 cm high.

The palace it sits in is older and quieter: 1540, by Bartolomeo Baronino for Cardinal Capodiferro, with a stucco-encrusted courtyard facade that is itself worth standing in before you look down the arcade.

It was built to be looked at from one place. That is the whole construction logic of the colonnade: every dimension is calculated for a single viewing point on the courtyard axis, and the effect exists only there. Walk a few metres to the side and the columns are visibly different heights and the floor visibly slopes.

The build is therefore an exercise in controlled deception rather than in engineering difficulty. Borromini had the geometry worked out by Giovanni Maria da Bitonto and then executed it in masonry: shortening the columns in series, raising the paving, lowering the vault and narrowing the walls, each by an amount that the eye reads as distance.

The palace around it came first, in 1540, and the gallery rooms were arranged for Cardinal Spada's pictures in 1636-1637, before the perspective was built. The colonnade is an addition to a finished house, which is part of why it sits off the courtyard rather than on an axis of the building.

Which day is it closed? Tuesday. Not Monday — this is the exception among Rome's state museums.

How long is the colonnade really? The gallery's own page does not give a figure; it says only that a short gallery is perceived as a long colonnade and that the statue is in reality much smaller than it appears. Wikipedia gives an apparent 37 metres against an actual 8, and a statue 60 cm high.

Who built it? Francesco Borromini, in 1653, with the scientific and mathematical calculations by the Augustinian father Giovanni Maria da Bitonto.

Can I walk down it? No. It is seen from the courtyard end.

How much is it? EUR 6, reduced EUR 2, free on the first Sunday of the month.

Do I need to book? Not as an individual. Groups of more than six must book.

Is the whole palace open? No. Palazzo Spada houses the Council of State; visitors see the gallery and the courtyard.

How long does it take? About an hour.