The Church of St. Achillius is situated in the city of Arilje and was the see of the Eparchy of Moravica (Moravička). The first church was probably built in the 11th century, whereas the present-day church was renewed by the Serbian King Dragutin (reigned 1276-1282) in the year 1296 (Sp. 87), as seen on the inscription in the drum. It is a single nave edifice with a low transept, a semicircular apse and a dome, anarthex and an exonarthex. It belongs to the Raška architectural style. The façade is decorated with lesenes and blind arcades. The exonarthex with a dome was added later. The church was fresco painted with portraits of King Dragutin and his brother the Serbian King Stefan Uroš II Milutin (reigned 1282-1321) as ktetors, Dragutin's wife the Arpad Princess Katalin of Hungary, their sons Vladislav and Urošica and several bishops of the Eparchy of Moravica. The church is a mausoleum of Dragutin's son Urošica.