This country's highest point is just 4.6 metres above the sea

Tuvalu, a Pacific nation of nine coral atolls, tops out at only 4.6 metres above sea level at its single highest point. Most of the country sits far lower, making it one of the places most exposed to rising seas on Earth. Some projections suggest parts could become uninhabitable within decades.

— Central Intelligence Agency, The World Factbook — Tuvalu country profile, Geography section