Why was Europe interested in exploration at the beginning of the 15th century?

They first wanted to find another route to the Asia while byping the Ottomans who were located in the middle East. So they thought of a Western route as they knew the world was a sphere. But instead they stumbled into the Americas. They found land, peoples and later gold. This then drove the desire to explore and find other inhabited or non inhabited lands not known to the Old world.