The Piazza San Marco is L-Shaped, with the smaller part fronting the lagoon, in front of the Palazzo Ducale, called the Piazetta. This was the center of public life in Venice, and also where all public executions took place, between the two pillars. The pillars were stolen from Egypt in the eleventh century, and executions have taken place there since then. For this reason, superstitious people avoid walking between them, although given their prime position on the tourism map and the millions of tourists milling about, it's hard to avoid. The state library is on the other side of the piazetta. Built in the sixteenth century, the roof collapsed almost immediately after the building's completion, landing the architect in the Doge's prison.