I’m sure many of you are familiar with the Ville series that is playable through Facebook. After FarmVille became one of the most popular games on the internet, Zynga released several other versions as well.

Now there’s CastleVille, and it has certainly taken Facebook by storm. In just under a week, CastleVille has garnered 5 million daily active users — meaning it’s growing faster than any other Zynga game did at this stage.

“CastleVille crossed the 5 million active user threshold Sunday night, just six days after its release. By hitting that milestone, CastleVille‘s growth has outshined other recent introductions from the company, including FrontierVille, which got 2.6 million DAUs (daily active users) in its first six days and CityVille, which received 3.2 million.”*

While CastleVille is rapidly growing in popularity, it still has a long ways to go before catching up to CityVille, which is currently the most popular game on Facebook with over 100 million users.

*Mashable