This building is very spacious, and the floor is completely covered with monumental slabs of marble, covering the graves of the knights.

The ceiling is ornamented with beautiful frescoes, and the walls are sculptured from ceiling to floor with arabesques, leaves, and flowers, in sandstone.
All these ornaments are richly gilt, and present a peculiarly imposing appearance.

The side-chapels contain numerous monuments, mostly of white marble, and one single one of black, in memory of celebrated Maltese knights.

At the right-hand corner of the church is the so-called "rose-coloured" chapel.

It is hung round with a heavy silk stuff of a red colour, which diffuses a roseate halo over all the objects around.