Other cities have suburban sprawl; Venice has primordial monasteries floating in teal-blue waters. To the south, the seaward side of the lagoon is sheltered from the Adriatic by the narrow strip of the Lido, for centuries the beach and bastion of the city. Smaller islands dot the foreground of remarkable views back across the lagoon to San Marco: Sacca Sessola, San Lazzaro degli Armeni, San Servolo and San Giorgio Maggiore. In the past they served the Republic well as quarantine islands, convents for wayward nuns, hospitals and mental asylums. In the northern reaches of the lagoon, Santa Maria Assunta marks the first settlement on the lagoon, its glittering mosaics telling cautionary tales of lost souls banished from a golden heaven filled with lagoon poppies.