9 days in Taiwan

Hi all,

Heading to Taiwan from the 4th of April to the 14th. My partner and i will in Taipei for 4 days and then we are looking for a second place to stay for a few days. Our last night will then be in Taipei again before flying out.

Looking for any recommendations for the 2nd place that has more nature, hikes, possibly a beach nearby, thermal hot springs etc. Ideally this place would be easy to get to via train aswell.

Thankyou!