The Japanese (1921) was the world's first purpose-built aircraft carrier, although the initial plans and laying down for (1924) had begun earlier. Both "Hōshō" and "Hermes" initially boasted the two most distinctive features of a modern aircraft carrier: a full-length flight deck and a starboard-side control tower island. Both continued to be adjusted in the light of further experimentation and experience, however: "Hōshō" even opted to remove its island entirely in favor of a less obstructed flight deck and improved pilot visibility. Instead, Japanese carriers opted to control their flight operations from a platform extending from the side of the flight deck.