What does "I had no idea that Central Park is so huge." mean in English for Spanish?

In English for Spanish, "I had no idea that Central Park is so huge." means:

No tenía ni idea de que Central Park fuera tan enorme.

Listen to "I had no idea that Central Park is so huge.": (If you have an HTML5 enabled browser, you can listen to the native audio below)

This is a phrase that is used in the GamesForLanguage English for Spanish Language Game in the following scenes:

• English for Spanish 4, Level 2, Scene 3