Murano's furnaces have burned without interruption since 1291, when the Venetian Republic banished all glassmakers to the island to contain fire risk and protect trade secrets. For seven centuries, this exile created the world's most concentrated glassblowing district. Today, the island's 600 residents support forty working furnaces, each operating under guild regulations that pre-date the Italian state. The Museo del Vetro on Fondamenta Marco Giustinian houses 4,000 objects spanning Roman fragments to contemporary installations, chronicling techniques refined across generations of master glaziers. Burano's chromatic façades emerged from practical necessity. Fishermen returning in lagoon fog navigated by the color-coded exteriors of their homes, a system formalized in the seventeenth century when the Serenissima required municipal approval for each hue. The island's lace school, established in 1872 to revive a declining craft, still teaches the punto in aria technique that distinguished Burano needlework from Venetian competitors. Production declined from 6,000 lacemakers in 1900 to fewer than thirty certified artisans today, most concentrated in the Museo del Merletto. Torcello sustained 20,000 inhabitants during the Byzantine period, its wealth built on salt production and strategic position along Adriatic trade routes. Malaria and silting canals depopulated the island by the fifteenth century, leaving the Basilica di Santa Maria Assunta as the lagoon's oldest structure. The cathedral's twelfth-century Last Judgment mosaic covers 300 square meters of the western wall, Byzantine iconography preserved in a church predating Venice itself. The campanile offers the lagoon's only 360-degree view without modern intrusion, 55 meters above marshland that reverted to wetland after the population collapse. Venetian lagoon islands tours depart hourly from Fondamente Nove, the northern waterfront district that replaced Rialto as the primary embarkation point in the nineteenth century. Most itineraries allocate ninety minutes on Murano for furnace demonstrations, sixty on Burano for the lace museum and canals, and forty-five on Torcello for the basilica complex.