Taiwan's 7 largest Metro Areas
Taipei–Keelung metropolitan area | 7,048,243 | Dark blue, in the north | |
Taichung–Changhua metropolitan area | 4,280,000 | Green, sort of in the middle | |
Kaohsiung metropolitan area | 2,367,591 | Brown, in the south | |
Taoyuan–Zhongli metropolitan area | 2,229,354 | Pink, in the north | |
Tainan metropolitan area | 1,886,000 | Red, in the south | |
Hsinchu metropolitan area | 1,121,693 | Light Blue | |
Chiayi metropolitan area | 475,465 | Light Orange, in the middle | |
Right away you'll notice that the dark blue, pink, and light blue metro areas are basically connected. That is essentially one continuous & connected urban area of 10+ million people, but administratively it is divided into multiple cities. The main airport in Taiwan is for instance technically in Taoyuan, but it takes about 35 minutes on the express train to get to central Taipei from there. Taipei City is also surrounded on all sides by New Taipei City. If you look at the blue blob on the map (in the north), it's got two cities inside it - that's Taipei and Keelung cities - The part of the dark blue blob outside of those boundaries is New Taipei City.
This sort of urban connectivity extends for most of the western coast, even if the above map doesn't really speak to that very well. There are a lot of smaller towns in between the larger ones, especially in the middle of the island (on the west coast anyhow). There are some farms here and there, but as you look out the window from a train riding along the west coast, it might as well be one large continous city from north to south.
The southern cities of Kaohsiung and Tainan are also very close to each other (but not as close as Taipei is to its surrounding cities). Kaohsiung's metro line's northernmost station is very close to where Tainan begins..
Surprisingly enough (at first glance anyhow) Kaohsiung is actually considered to be Taiwan's second city, even though Taichung has more people living in it (Even without the other cities in its metro area, Taichung has a population of 2.8 million) This sort of makes more sense if you explore these two cities on foot. Kaohsiung feels like a proper second city, it's got a really cool harbour and 2 subway lines (+1 light rail loop). Taichung only has 1 subway line that sort of loops around the city in a weird way. It's way easier to get around Kaohsiung, and it seems to have more unique/marquee sort of buildings and attractions, it's just got that "second city" feel in a way that Taichung doesn't.
Out of all these cities I have not visited Hsinchu, Zhongli, Keelung, Changhua, or Taoyuan. Left myself some cities to explore for next time