Sistine Chapel

The chapel exterior is deliberately plain — a brick box that gives nothing away — and the shock of entering the Sistine Chapel is entirely intentional: the walls and ceiling are covered in fresco by the finest painters of the 15th and early 16th centuries, but it is Michelangelo's contribution that rewrites the room's proportions the moment your eyes adjust and look up, and the room becomes about the ceiling in a way that seems physically impossible given that the walls are also covered in paintings.

The ceiling fresco is not a single image but a programme: nine scenes from Genesis from the Creation of Light to the Drunkenness of Noah, bounded by a fictive architectural framework of prophets, sibyls, ignudi and ancestors that makes the barrel vault appear to have windows cut through it into a painted sky of infinite depth, and the illusionistic architecture is so convincing that most visitors initially mistake it for real moulding and wait for the paint to end.

The ceiling reads differently at different hours: morning light from the east makes the figures appear to rise from their niches; by afternoon the gold leaf in the background catches the western light and the whole ceiling seems to ignite in a way that makes the colours appear more saturated than any photograph suggests, and Michelangelo apparently arranged his colours to exploit exactly this effect of natural light transforming the palette.

The Last Judgment on the altar wall, painted 25 years after the ceiling and covering approximately 1,300 square metres, has a completely different emotional register: the serene idealised bodies of the ceiling are replaced by muscular, writhing figures ascending and descending in a swirling composition whose scale is almost unbearable without the context of the ceiling above it, and the naked figures scandalised Cardinal Carafa enough that he called for the fresco to be whitewashed.

Michelangelo worked lying on his back for four years on the ceiling and standing on scaffolding for another four years on the Last Judgment, and the physical effort shows in the difference between the two works: the ceiling figures have an otherworldly ease that the Last Judgment figures, painted with a more desperate energy, do not quite share, as though the ceiling was painted by someone who believed in the theology and the Last Judgment by someone who had come to doubt it.

The side walls, painted a decade earlier under Pope Sixtus IV by Botticelli, Perugino, Ghirlandaio and others, are often overlooked in the rush to see Michelangelo — a serious mistake, because the sequence of the Life of Moses and the Life of Christ is itself a masterpiece of Renaissance narrative painting, and Botticelli's scenes in particular reward the extended attention that most visitors, tired from the museums route, rarely give them.

Michelangelo's ceiling and Last Judgment together represent the most consequential fresco cycle in Western art and shaped everything that followed.

The chapel is also the site of the papal conclave, where the Catholic Church's cardinals elect each new pope — making it the most politically significant interior in the world.

The combination of Botticelli, Perugino, Ghirlandaio and Michelangelo on the same walls gives a unique side-by-side view of the full range of Renaissance painting talent.