The Heart of Liberty City
The Heart of Liberty City is located inside the Statue of Happiness.
While playing GTA IV players can find a gigantic beating heart inside of the Statue of Happiness on Happiness Island. The heart is held up with chains and there appears to be arteries and veins leading from the Heart to the statues exterior.
To enter the statue and see the Heart, players will need to gain access to the upper platform of the statue. Once there you will see 4 doors all around the statue
Walk around to the southern door and you will see a pair of signs which read, “No hidden content this way.” Unlike the other doors on this level you will be able to walk through this one (the door doesn’t actually open, you just walk through it). Once inside the statue simply climb the ladder in front of you and you’ll be face to face with the Heart of Liberty City.
In the DLC “The Ballad of Gay Tony“, players will find a bloodstain outside of the door which will allow you to walk through it.
Shooting or throwing explosives at the heart will have no affect on the Heart itself, but it has been discovered that shooting an RPG at the Heart will trigger the “… flying rats left in Liberty City.” message which signifies you’ve killed a pigeon (hidden package).