The island of Lazaretto is known primarily as a place of medieval quarantine against various diseases, primarily from the plague. The island gave its name to the word infirmary that exists in many languages ​​of the world.

The quarantine on the island was established by order of the Doge of Venice after a severe plague in 1348. It existed until 1630. The hospital and barracks occupied the entire territory of the island. In the 17th century, the hospital ceased to exist. The buildings on the island housed a military garrison; fortifications with an artillery battery were built. In the 19th century, stray dogs were sent to the island from the mainland. No one has lived on the island since the 1960s. During excavations in the 2000s at the island's hospital cemetery, archaeologists unearthed more than 1,500 plague skeletons dating back to the 15th-17th centuries.