It is one of the smallest Romanesque churches in Sardinia, but its main feature, which is clearly visible on the façade, is an architrave with images, carved in relief, of five anthropomorphic figures, one of which is upside down. This work, unique in Sardinian medieval sculpture, can be boasted only by the Church of San Michele Arcangelo. The sanctuary was built in the mid-13th century on a small hill that currently represents the outskirts of Siddi, built from brown and yellow marl, sandstone and basalt. The layout has two naves, but quite strangely, only one of the two - the one to the south, which is wider than the other - ends with an apse. The roof is made of wood, with a gabled roof in the main nave and a single-pitch roof in the ‘smaller nave-aisle’.

On the façade, you will notice only one hanging arch. Originally, there was probably a series of arches that ran along the entire façade, but they were lost following renovation work. The two portals both have architraves, with a rounded relieving arch. You will be impressed by the architrave on the left, where the sculpted figures appear within four panels, divided by vertical bands decorated with intertwined diamond shapes.