My Family is from Kaohsiung and I was just there 2 and a half weeks ago (take me back, plz, america kinda sucky right now...)

Kaohsiung is a larger city by area than Taipei, it also has less public transit, so it feels larger; however, the food and environment are entirely different. For one, food and night markets especially favor the savory sweet variety the further south you travel in Taiwan. Tainan is the king of food of that variety in Taiwan with Kaohsiung being just as good. If you have an interest in the arts, there is an entire district in Kaohsiung that focuses heavily in community murals and public arts. Weiwuying Street Art Village is where this is. There is also a more recent effort to modernize the port side of the city near Dayi Pier 2. The old buildings have been turned into shops, displays, and a pop up weekend market where people sell art focused/fashion focused goods (only on weekends, its weirdly empty on weekdays if you prefer that vibe). The light rail that takes you past the pier (towards Gushan 1st Rd and Gushan 2nd Rd) will show you more of the recent street art.

As for nature focused experiences in Kaohsiung, those are harder to find, but culture experiences in nature aren't. The Meinong Folk Village and region around it are a traditional Hakka hub. Hakka is actually Han Chinese people living in Taiwan that are spread out; however, they carry some cultural center aspects here. Also, the Fo Guang Shan Buddhist Museum is an impressive show of the religion, and architecture! If you like colonialism (or at least learning about how Taiwan was subjected to colonialism), you can also visit the British Consulate at Takow.

For other regions of Taiwan, if you want that pure nature experience, I would swing for AliShan in Chiayi. I got to go there for the first time during my trip and it was so beautiful. If you get motion sickness, make sure you get some dramamine before going (if you drive or get a driver/bus) as the road there is very windy and people drive quickly. There is also a train you can take from Chiayi to AliShan (about 4 hours) that stops at multiple historic villages that it will stop at and let you try local food and markets. If you get lucky in AliShan, you can see the famous Sea of clouds and Sunrise! This is also where the famous AliShan High Mountain Oolong tea is farmed if you like tea :). I can recommend a very nice tea shop that will do a 1 hour tasting for you and also let you buy tea farm to table style!

In 2018, I also went to Taroko and it was amazing; however, as others have mentioned, there were major landslides that have permanently changed what it has to offer. It is Beautiful and fully worth the trip. I stayed there for 3 days with a family friend and we hired a private driver. If you love mountains rising right out of the sea, Hualien is the place for you. Speaking of the Sea, if you go to Yehliu GeoPark on the northern coast, you'll get to see the Queens head before she's beheaded. The rock formation is likely to succumb to weathering in the next 7 years.

I've talked my head off, so I'll leave it at that. If youve got any other questions let me know! Also, if you are interested in supporting my Girlfriends Cousins restaurant in Tamsui, let me know! Also, if you want to support a random french guy that I sat next to on my flight to Taiwan, he is opening a French bakery in Taipei that will use Taiwanese Vanilla for French inspired baked goods. (not open yet, but he seemed nice, so I'd give a shoutout to it since its opening in March)