Not that far by road (2 hours) & convenient & cheap by rail, Valencia is one of our favourite Spanish cities. As well as the science park, cathedral & usual churches, bullring with museum, it has so much more to offer. The post office, train station (Norte), & our favourite the Plaza Redonde are all worth a look.
Our daughter lives just outside, so we go often. This year, our granddaughter is a fallera (the costume costs an arm & a leg) & regrettably we won't be over there for Falla's (THE festival to Valencia)
There is a hop on hop off bus tour, & the city is compact enough to get around loads of the sights on foot.
Tip. If travelling by rail, & a pensioner, produce passport at station & buy a rail card before buying your ticket. Substantial saving on an already reasonable fare.