Why wouldn’t have western culture/Europeans have at least suspected that there might be a huge landmass across the Atlantic? Were there never any rumors or myths? Did it seriously take until the 1490s until someone in Europe decided to go take a look?

by paperchampionpicture
y_sengaku

While there will always be more to be said, I recently post a summary of the possible reception of Norse exploration narrative in medieval Europe in: I've often heard the argument that Vikings had rediscovered North America centuries before Columbus stumbled into the Caribbean. Did they know they were on an uncharted continent? If not, where did they think they were?, and I hope my summary as well as the linked post will cover OP's question.