The cycle of frescoes in the apse of the Basilica di San Francesco is one of the supreme achievements of Italian Renaissance painting. Piero della Francesca's series depicts the Legend of the True Cross — from the death of Adam to the Emperor Constantine's dream before battle — in a style of extraordinary geometric precision, pale luminous colour, and psychological calm.
The figures have a monumental stillness that looks almost modern. The composition of the "Dream of Constantine" — a night scene lit by an angel descending from above — is technically ahead of its time by decades. Entry is by timed ticket; the viewing time is limited, so come prepared to look carefully. The basilica itself, separate from the frescoed apse, is free to enter.