Sant'Anastasia may look like another Romanesque church from the outside (and after a few, you too, may yawn). However, the inside is a glorious riot of frescos and other artwork. Check out the chapel with the terracotta panels- you will never look at a simple flower pot again the same way.
Some of the frescos have been damaged by everything from fire to so-called "renovation." It is a miracle this gothic artwork survived the few hundred years when art from the middle ages was considered backwards and was removed. (Although a quick Renaissance plastering-over job usually helps preserve these pieces for those of us who now appreciate them.)
Even the floor is inlaid in ornate Escher-esque patterns of different marble. But what people most remember are the two gobbi- little hunchback figures that hold up the holy water fonts. Though perhaps not as appealing as Juliet's breast, a local superstition would have you to touch their backs for good luck.
A fee is charged for entrance unless you convince the staff that you are entering for religious purposes. No cheating, now! After all the inside is well worth the cost.