Studded with seashells, this ‘Moorish Castle’ was built in 1899 for an eccentric merchant, Arseny Morozov, who was inspired by a real Moorish castle in Spain. The inside (not open to the public) is sumptuous and equally over the top. Morozov’s mother, who lived next door, apparently declared of her son’s home, ‘Until now, only I knew you were mad; now everyone will’.