“In 2014, they invited the director of restoration of the Sistine Chapel. He entered here and exclaimed, ‘Why didn’t you tell me you had a Sistine Chapel in Valencia?’” our guide Konstantin, of Discovering Valencia, paused as my wife and I stared up in awe where beams of sunlight, glowing in the incense smoke, lit up a magnificent expanse of frescoes. “When you see the church from outside, you are not thinking to go in.” True, the 15th-century church of St. Nicholas of Bari and St. Peter Martyr is Gothic in style, so one might expect a more severe interior. Nothing had prepared me for the saints and angels of the Baroque ceiling, which invariably makes one think of Michelangelo’s masterwork. The paintings present scenes of the patron saints’ lives and a few historical figures, including the archbishop who commissioned this upgrade in the 1690s. The brilliant restoration was completed …