Only commenting on this because "unknown" feels a bit off, especially in the context of greatest human achievements.
Much of the Polynesian Triangle and Indian Ocean trade routes were established hundreds and in some areas thousands of years prior to Magellan. Tierra del Fuego (Straight of Magellan) had been inhabited by nomadic seafarers for thousands of years. Magellan's personal circumnavigation requires including his previous voyages to the Malay peninsula via India.
Circumnavigation a mere ~30 years after Portugal first reached the Cape of Good Hope is extraordinary. Full stop.
But tweaking perspective shows how reaching the Indian Ocean pulled back the curtain on an already developed world, where interconnected maritime trade included both China and Mozambique. The 1300s scholar Ibn Battuta of Tangier visited Beijing, Timbuktu, Singapore, Kenya, and Constantinople within 30 years. Technology and motivations unique to Europeans stitched together routes across the world and did it in a way that enabled others to quickly follow, but there were precious few places visited that someone else didn't already traverse and call home.
Much of the Polynesian Triangle and Indian Ocean trade routes were established hundreds and in some areas thousands of years prior to Magellan. Tierra del Fuego (Straight of Magellan) had been inhabited by nomadic seafarers for thousands of years. Magellan's personal circumnavigation requires including his previous voyages to the Malay peninsula via India.
Circumnavigation a mere ~30 years after Portugal first reached the Cape of Good Hope is extraordinary. Full stop.
But tweaking perspective shows how reaching the Indian Ocean pulled back the curtain on an already developed world, where interconnected maritime trade included both China and Mozambique. The 1300s scholar Ibn Battuta of Tangier visited Beijing, Timbuktu, Singapore, Kenya, and Constantinople within 30 years. Technology and motivations unique to Europeans stitched together routes across the world and did it in a way that enabled others to quickly follow, but there were precious few places visited that someone else didn't already traverse and call home.