You can take flight from Istanbul to Kayseri airport and take bus to Uchisar. It is cheaper way to go but take longer time about 4hours.
Uchisar is famous with Uchisar Castle and valley. It is closed to Derinkuyu underground city where it is deepest underground city. You can sign local tour to reach Derinkuyu. In the morning, you are able to see a lot of hot air balloons in the sky. The view is super amazing.
I would say this city is the most friendly city. People are super friendly and chill. For those who love Sightseeing, nature activity and photo shoot.
.. this city is the best choice:)