Question

What caused Columbus to think he reached Asia?

Answer 1

He made mistake in estimating size of earth..He calculated size more than half..Hence he thought he reach Asia without knowing he discovered a new American Land.

Answer 2

He believed he had sailed all the way around the world and didn't know that North America existed. However, he didn't really think he had reached Asia. He thought he had reached the East Indies, an island chain containing Indonesia.