I know this is two geography posts in a row, but I learn what I learn so that’s what you get.
Port Royal, the former Jamaican trading port famous for privateers, rum, whores and pirates* — you *have* seen Pirates of the Caribbean by now, I assume — is underwater. It is the only sunken city in the New World and got to be that way in June of 1692 when an earthquake plunged 33 acres of the city into the harbour.
Though there was a lack of seismic recording technology, historians can accurately place the time of the earthquake at around 20 minutes to 12 because a pocket watched dating from 1686, built by a French watchmaker living in the Netherlands, was found near one of the sunken forts; it was stopped at 11:43.**
*You know, the Vegas of the Colonial Caribbean.