St. Mark's is the 5th largest cathedral in the world. Hundreds of pigeons filled the square in the mornings eating from people's hands and perching on their outstretched arms. Later in the day was watched mass as water started rising up from between the stones in the square. Ramps were put in place so people coming and going from the cathedral wouldn't track in water. We even saw a postcard of a gondola floating across the square! Even hotel lobbies flood. People just get use to the tides.