Question:  Nikolai Mikhaylovich Albov is credited with being the first European explorer to have traveled extensively over an archipelago off the southernmost tip of the South American mainland across what strait?         
Sentence (from "Tierra del Fuego"): Tierra del Fuego ( , ] ; Spanish for "Land of Fire") is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan.
Relevant evidence: Yes