Where are the 3 kings from?

The song says that they're from the Orient (Asia), but The Bible says only that they're from "the east", which I guess would have to be somewhere in Asia if speaking with respect to the Middle East.

BTW, the Bible states that they brought three gifts to Jesus, gold, frankincense and myrrh, but it gives no other clue regarding how many of the wise men there were. It became popular to think of there being three wise men because of the number of gifts, but we really have no idea how many there were.