Worth taking the boat from near Pier 2 to here and spending an afternoon. Is on the site of a village that was razed to make way for development, and the museum dedicated to the township that once existed here is quite interesting. Quite cool to sit in the revolving restaurant and watch the massive container ships go by
It's well worth getting the ferry here, hiring a bicycle and enjoying the sea breeze along the coast path. Some good food to be had here, and you can sit on the beach and watch the surfers - or join them!
The aquarium's actually not that special, but the lake is a good place to get away from the noise of the city. Small entrance fee if you're not a Kaohsiung resident.
Lots of exhibitions to see, things to buy, and places to eat and drink. Easily accessible via the MRT. Surprisingly relaxed atmosphere for somewhere so close to the city centre.
A great place to spend a day or a half-day. You can walk around the lake and visit the famous tiger and dragon, as well as temples and other sites. Some good spots to relax and grab some food and drinks nearby.
A tranquil Buddhist monastery with some beautiful scenery, definitely worth visiting if you come to Kaohsiung. Can be extremely busy at weekends and holidays though. The actual monastery area is wonderful and really makes you contemplate things whether you're religious or not.
There is also the newer Buddha Memorial Center nearby, but in my opinion this is hideously over-commercialized and is more like a shopping mall than a place of worship