The most striking feature of the temple's interior is its absolute ornamental simplicity. We have already seen this austere style in the Chapter House. The church shares another feature with that hall: the pointed barrel vault covering the nave, which represents a transition to the Gothic style and provides a pleasant sense of spaciousness.
The interior of the apse is covered by a quarter-sphere vault, as was customary during the Romanesque era. Beneath the apse lies a hidden passageway that descends via a spiral staircase and branches out into three underground galleries.