Must tender to get there, so allow some time. We took an afternoon tour through Princess to the Castle with a city tour. Excellent tour and great guide. It was a Friday afternoon so Rush hour traffic getting back to the tender area is a concern. Be careful of this if you explore on your own. Luckily, the bus had it's own "bus only" lane, so we scooted right by all the backed up traffic. The Castle is the highlight, and we had about 2 hours to explore it.