Do you know any cool places I can go to in Grand Theft Auto IV? Like secret spots?

Question

I've finished the game, and I would really like to know what I can do after I did.

Answer 1

www.whattheydonotwantyoutoknow.com

Type that into the ingame internet to see a conspiracy/secret style website that lists many dark secrets about Liberty City.

Or try www.liesdamnlies.com

this is also a conspiracy site but doesnt have the good stuff on.  

Answer 2

Theres a hidden stroller:

You can find this stroller abandoned on a sandy hillside just southwest of Francis International Airport, and while it looks like just another piece of garbage cluttering up the game world, it's actually a lot more ominous than that.Think about it: have you ever seen a kid in a GTA game? No, you haven't. In fact, with the exception of Louise's baby in Vice City Stories (who doesn't count, because she only shows up in cutscenes) and a few radio bits, there's never even been evidence of kids in the GTA world.

Or there wasn't until we saw this stroller, anyway, which sits alone, parked on a hillside in more or less pristine condition, with no parents or baby in sight. Just a rusted-out car and some big, dangerous-looking rocks. If you stop to think about it, this one lonely object tells a whole sordid story.

Answer 3

The Heart of the City.

Fly a helicopter to the Staue of Happinees, and theres a door near thetop, go in and see the, well youll see for yourself.