The most important monuments of Atri are the Cathedral of Santa Maria Assunta (late XII century); Palazzo Ducale (Acquaviva), a fortress built in the highest point of the town, now the seat of the municipality; the Medieval walls with Porta Macelli and Porta S.Domenico; Museo Capitolare, Church of San Francesco, with a beautiful Baroque flight of stairs and Church of San Domenico, with two fine paintings by Giacomo Farelli (XVII century)
Andrea de Litio (also spelt Delitio), one of the greatest Abruzzese painters, achieved a wonderful fusion of native and international elements. He painted frescoes in many parts of Abruzzo, and some of his paintings are in museums as far as Baltimore and New York. His acknoledged masterpiece is the fresco cycle in the Cathedral of Atri. Very little is known on his life. He must have been born about 1420, and for long time his place of birth was uncertain: da Lecce in Apulia, Guardiagrele, Sulmona, Atri. But the presence in Marsica of two juvenile works, led scholars to believe he was from Lecce Vecchia, called in Lombard times Litium, which after the 1915 earthquake was abandoned when the population rebuilt their village, now Lecce dei Marsi, down in the plain.
At the time this area of Abruzzo was poor, afflicted by periodical famine, devastated by earthquakes and invading armies. A landscape of valleys and mountains, which Andrea De Litio about 1440 left for Umbria and Tuscany, where his artistic personality could better develop. Decades later he returned to the other Abruzzo along the coast, where he left the great works of his maturity. He was again in Abruzzo in 1473, when he signed and dated the giant San Cristoforo on the outer wall of Santa Maria Maggiore, Guardiagrele, and in 1480 he was working on his masterpiece in Atri.