You've heard of Atlantis (sinking into the sea) and Gondwanaland, even perhaps the lost island continent of Mu – now we have Zealandia – see https://phys.org/print406523221.html
An area encompassing New Caledonia and New Zealand, ninety four per cent of which is currently submerged, appears to be a lost continent (implying it consists of crust rather than sea bottom basalt). It even has mountain chains.
The story, with pictures, is also at www.express.co.uk/news/world/768426/ZEALANDIA-DISCOVERED-scientists-find…
… was this a stepping stone for human migration between Austronesia and South America? If you included the East Pacific Rise and the Easter Island Ridge into the equation it may have been possible for people from SE Asia to have reached the Americas within the last 100,000 years (but would require a change in earth's geoid to make it work).