Senj’s principal place of worship is thought to date from the eleventh century, and fragments of Romanesque brickwork can still be seen on the lower parts of the west-facing façade. The Cathedral was severely damaged in the Allied bombing raids of September 1943, after which the exterior was reconstructed in a selection of different materials – thereby explaining the building’s current mix-and-match appearance.
Inside, each row of pews is engraved with a character from the Glagolitic alphabet (those on the left-hand side spell out the words ‘Katedrala Senj’, just in case you’re wondering). Decorating the pillars on either side of the nave is a series of wooden reliefs illustrating the Stations of the Cross, carved in 1958 by Ivan Kozarić, a leading Croatian sculptor more famous for his abstract work (such as the enigmatic bronze-coloured sphere that adorns the pedestrian zone in the centre of Zagreb). Main highlight on the left side of the nave is the baroque Altar of the Angels, with Raphael the Healer in the centre, and St Michael spearing a frowny-faced demon to his right. The curtained glass cabinet beneath the altar contains the mummified remains of an early Christian martyr brought here from the catacombs in Rome. Posed in a reclining position with head propped up on an elbow, the centuries-old shrivelled corpse looks as if it is relaxing at a country picnic. Nearby, an ornate baroque pulpit dating from 1757 bulges from a pillar like a gilded fungus. Over on the opposite side of the nave is a charming nineteenth-century effigy of the Virgin and Child mounted on a canopied trolley, traditionally paraded around town on the feast day of Our Lady of Mount Carmel (16 July).  
One of the cathedral’s most revered artefacts is the renaissance relief of the Holy Trinity immediately to the right of the main entrance as you face the altar. Dating from 1491, the relief bears a touching portrayal of the Crucified Christ alongside the earliest known stone-carved example of a šahovnica, the chequerboard pattern that appears on the Croatian coat of arms.
Across the square from the cathedral, past the free-standing belfry, look out for the charming figurine of Suffering Jesus placed half way up the wall of a renaissance house.