Monterria is a fictional country. It is run by the King of Monterria and his children, Eloise and Alexander.
The King's brother, Robert the Terrible has been trying to retain the throne back, but ultimately fails.
According to Mike Nawrocki, Monterria means "Land of Mountains" and is named after a small village in Northern Columbia, so it's located somewhere in South America.
It's only mentioned in The Pirates Who Don't Do Anything.
- Originally, Phil Vischer wanted the country to be called Moritania. However, it was changed due to the fact the name's similar to an African country, Mauritania.