St. John’s Co-Cathedral (Kon-Katidral ta' San Ġwann) is a stunning Mannerist cathedral in Valletta, with one of the finest high Baroque interiors in Europe. It’s a co-cathedral, which means it shares the bishop’s seat with another cathedral, in this case with St. Paul’s Cathedral in Malta’s former capital of Mdina. Visitors can explore the multiple ornately decorated chapels and see two masterpieces by Caravaggio.