What do treasure cards indicate in the Forbidden Island cooperative game?

Artifacts to collect

In Australian Christmas tradition, what beach activity is common on December 25th? Which actress starred as Mia Thermopolis in "The Princess Diaries"? What position does Viktor Krum play in Quidditch? Which Marvel superhero grew up in Hell's Kitchen? In "Holiday Inn" (1942), Bing Crosby introduced which classic Christmas song?