St Basil’s has several names, but the one it is most known for was given to it after Basil the Blessed, a “holy fool” who deliberately walked barefoot and abandoned clothes and his home. He was close to people and stood for the truth, and even Ivan the Terrible was said to be afraid of him. The Cathedral was built in the 16th century, and many periods of its life are shrouded in mystery. So what secrets does it hide?