Napoleon called the Piazza San Marco the finest drawing room in Europe - an enclosed space of extraordinary proportion, bounded by the Basilica, the Campanile, the Doge's Palace, and the arcaded procuratie that line three sides. The space evolved over centuries: the Basilica's current form dates to the 11th century, the Campanile to the 12th (rebuilt after collapse in 1902), the Procuratie Vecchie to the 16th. The proportions feel inevitable, as if the square had always existed exactly as it appears.

The Basilica of San Marco holds the remains of St. Mark the Evangelist, stolen from Alexandria in 828 and smuggled past Muslim customs officials, according to legend, under a cargo of pork. The church that houses them is Byzantine in style, built by Venetian architects imitating Constantinople, its interior covered with gold mosaics that gleam in candlelight. The Piazza floods regularly now - acqua alta, high water, that turns the drawing room into a wading pool. Tourists splash through on raised walkways; residents long ago learned to plan around the tides.

The Grand Canal winds through Venice in a reverse S, the main traffic artery of a city without roads. The canal is lined with palazzos - the Venetian term for the mansions of the merchant aristocracy who governed the Republic. The Ca' d'Oro, the Ca' Rezzonico, the Palazzo Grimani - each facade represents a family's wealth and taste, Gothic tracery giving way to Renaissance classicism as architecture evolved while the canal remained.

Traffic on the Grand Canal today is water buses, water taxis, delivery barges, and the gondolas that tourists hire for prices that would have shocked the aristocrats who once used them as transportation. The vaporetto that runs the canal's length is public transit, crowded during rush hour with commuters heading to the train station, emptier at night when the palazzos light up and the canal becomes theater. The palazzo interiors, many converted to hotels or museums, hint at what the Republic's wealth once meant - Tiepolo ceilings, Murano chandeliers, the accumulated beauty of merchants who had money and nowhere else to spend it.

Venice sinks and the sea rises, the combination accelerating. The city has always dealt with water - the acqua alta that floods the piazza is not new - but the frequency and height of floods have increased. In November 2019, the tide reached 187 centimeters, the highest in fifty years, flooding St. Mark's Basilica and damaging mosaics that had survived centuries. MOSE, the massive flood barrier system, was finally activated in 2020 after decades of construction and corruption scandals.

The barriers help but cannot solve the underlying problem: Venice was built on a lagoon that is changing. The industrial zone at Marghera drew water for manufacturing, accelerating subsidence. Cruise ships that once docked near the piazza were banned in 2021 after years of protest - their wakes damaged foundations, their bulk dwarfed the human-scale city. Climate change raises seas regardless of what Venice does; by some estimates, the city could face regular flooding of two meters or more by century's end. The question is not whether Venice will survive but what survival means for a city that might become uninhabitable.

Venice proper holds roughly 50,000 residents - less than a third of its postwar population. The departure accelerates each year: housing costs exceed wages, daily life requires navigation that the elderly cannot manage, the infrastructure of a normal city - supermarkets, schools, hospitals - has shrunk as residents left. The cruise ships and day-trippers and Airbnb guests who now dominate the city do not need residents; they need picturesque backdrop.

The city has tried to slow the exodus: restrictions on short-term rentals, subsidies for families, incentives for businesses that serve locals. Nothing has reversed the trend. A generation of Venetians has moved to Mestre, the mainland suburb, commuting to jobs in a city they cannot afford to live in. What remains is increasingly elderly, increasingly dependent on tourism, increasingly staged. The city built by refugees escaping catastrophe may end as a museum piece, beautiful and empty, maintained for visitors who experience what no one any longer inhabits.

The lagoon made Venice and may unmake it, but for now the water remains the city's defining feature. The islands that dot the lagoon - Murano with its glassmakers, Burano with its painted houses and lace, Torcello where Venice began before Venice existed - extend the city beyond its famous center. The vaporetti that connect them are commuter ferries for locals and excursion boats for tourists, the lagoon functioning as both barrier and highway.

The glassmaking that made Murano famous was moved there in 1291 to reduce fire risk to the main city; the industry continues, though competition from imports threatens what centuries of tradition established. Burano's colors were reportedly painted so fishermen could identify their homes from the lagoon; now tourists photograph the facades while the fishing industry that justified them fades. The lagoon is ecosystem and infrastructure, nursery for fish and highway for boats, the shallow waters that protected Venice from invasion now protecting it from nothing except perhaps irrelevance. The water gives the city meaning; whether it gives the city a future remains uncertain.