…or rectangular for that matter. St Mark’s Basilica is not exactly aligned with the square.
We found out by reading Secret Venice. There is a very small metal medallion under the arcade, opposite Sotoportego de l’Arco Celeste.
It is not easy to find , but after a careful search, we spotted it.
The medallion indicates the exact line of the basilica’s axis. If you stand on the medallion facing the basilica you can see the odd angle of the church.
I find little details like this fascinating. Secret Venice is full of great stuff like this. We walked around Venice for days with the book in hand, discovering all kinds of interesting things about this glorious city.