Colon, Panama port
Ditto on this port - it's such a lovely spot; however our experience was it is not safe at all!! It was Easter Sunday, and we thought that we would go to church to light a candle - we were not out a block and 2 police officers warned us of the area; we had an escort 'on bicycle' who followed us as we toured.
I would suggest as everyone else has is do a guided tour or better yet save your money and enjoy the ship.
Above all - enjoy your holiday.