Urban explorer, Sergey Prokopenko sees the hidden beauty that’s concealed within St. Petersburg‘s most striking architectural structures. When referring to the brilliance he finds while exploring many interiors, the photographer states, “It’s hidden from invaders behind closed doors and security locks, inside the courtyards. This is the world of century-old stained glass, old oak staircases and abandoned attics, which still keep the possessions of the long past occupants of the tenements.”

Before him, Prokopenko has the entire city of St. Petersburg, which is home to palaces, government buildings, mansions, and museums that act as architectural gems. “For me, finding such locations becomes somewhat of a gamble: you never know what to anticipate behind the closed doors—an angry janitor or a beautiful fireplace that hasn’t been affected by time,” the architecture blogger explains.