I mainly signed up for Gujo Hachiman Castle, and it's definitely worth climbing up to the main keep to take a look. The only downside is that we only stayed in Gujo Hachiman for an hour, so climbing up to the castle felt a bit rushed. In Hida Takayama Old Town, you must try Hida beef, and in Shirakawa-go, you definitely need to go up to the observation deck. Our tour guide, Liu Chang, gets 100 points! Before the tour started, she introduced the attractions in three languages (Chinese, English, and Japanese) and clearly stated the meeting times. The driver drove steadily. It was a very fulfilling trip, highly recommended.