HMS Sussex
HMS Sussex was an 80-gun third-rate ship of the line of the English Royal Navy, lost in a severe storm on 1 March 1694 off Gibraltar. On board were possibly 10 tons (330,000 troy oz) of gold coins. This could now be worth more than $500 million, including the bullion and antiquity values, making it one of the most valuable wrecks ever.
Archaeological site data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).