Guild Wars 2 has so many hidden secrets, and some of those include Mini Dungeons.

End of Dragons added multiple mini dungeons for you to explore and utilize as a great resource of farming Jade Runestones

Caudecus's Manor is the home of Minister Caudecus within the Shire of Beetletun, who is hosting a party celebrating the continuing peace treaty between humans and charr.

The Ascalonian Catacombs are an underground network of tunnels and crypts within Ascalon. They have several levels, and were built over a gaping cavern connected to the Underworld.