Dongyanshan National Forest Recreation Area

It's incredibly convenient, fast, and cheap to buy and use. It's much cheaper than buying tickets on-site, plus you get parking fees. At entry, staff simply scan your QR code and check your ID. Buying tickets on-site will result in a significant delay. I highly recommend it, but currently not all forest amusement areas offer this service. I've used it at Pat Sin Shan and here. It's truly convenient and saves money.