The Heart OF Liberty

[rean2]

Found something really cool, take a helicopter and go to the Statue of Happiness and find a door at the Statues feet, u should be on a square platform with a door in the center of each side. Go look for a Plaque that says "No Hidden Content Here", and from there walk STRAIGHT in to the door next to it. It doesn't open but u can walk through it. After that, go up the ladder and u should see the beating Heart of Liberty

Here's a guide
http://kotaku.com/385698/how-to-visit-the-beating-heart-of-liberty-city

EDIT: oops looks like somone already posted it, o well