The repeated, record-setting acqua alta events of late 2019 caused an estimated €300 million in damage to the Byzantine-style landmark — and floods are expected to get more frequent and severe as sea level rises. What’s more, the long-delayed MOSE floodgates in the Venice lagoon aren’t enough to protect St. Mark’s, which lies at one of the lowest points in the city and takes on seawater at tide levels well below what triggers the gates to rise. So engineers and architects are working on a €3.5 million set of extra flood defenses for the church. – Atlas Obscura