There’s a whole secret area of the Philadelphia stage in Tony Hawk’s Pro Skater 1 + 2. This secret skatepark is hidden behind a chain-link fence, and you’ll need to get there to get the “Liptrick 4 Skatepark Lips” challenge.
Thankfully, it’s actually pretty easy. There’s a wire leading up to some power lines, and all you have to do is grind your way up the wire (check out the video at the bottom of this article to see exactly how to do this). The power lines will come crashing down, and they’ll knock down the fence, letting you through.
You will have to unlock this area over again once you start the next session, but it’s not difficult once you know how.
Below, I’ve posted a video that shows the process of unlocking the secret skatepark in Philadelphia in Tony Hawk’s Pro Skater 1 + 2.
