Best inner-city park in Pittsburgh. You can hike or run or mountain bike and feel like you're nowhere near a city. It's plenty big to get in a good workout without having to loop around to the same place over and over. For mountain biking, some of the single track can be quite technical, and I recommend having someone familiar with the place show you around, because the trails are a little obscure and can vary widely in difficulty. It can be a bit of a disaster zone after rain or snow, so I prefer nice dry days.