Danshui.

This is a cute little city on the last subway stop of the MRT. It's at the mouth of the Danshui River and has had a lot of history of Dutch, Spanish, Chinese, and Japanese settlement. Along the river are neat shops with a boardwalk sort of feel (but without an actual boardwalk). The rest of the city winds up and down steep hills. There are tons of adorable cafes with beautiful views of the river and nearby mountains.