There are several music festivals that take place in the region of Castellón, on the eastern coast of Spain, which is close to the town of Oropesa del Mar. Here are a few examples:

1. FIB Festival Benicàssim: This music festival, also known as the Festival Internacional de Benicàssim, takes place in the town of Benicàssim, and features a range of international and national acts, as well as DJ sets and other performances. The festival takes place in July and has featured artists such as Lana Del Rey, The Chemical Brothers, and The Strokes.

2. SANSAN Festival: This music festival takes place in the town of Benicàssim in April. With an early date, the festival is celebrated every year during the Easter holidays, being the first alternative for a different holiday.

3. Arenal Sound: This music festival takes place in the town of Borriana, and features a range of electronic and pop music acts, as well as DJ sets and other performances. The festival takes place in August and has featured artists such as The Chainsmokers, David Guetta, and Martin Garrix.

4. Leyendas del Rock: This rock music festival takes place in the town of Villena, and features a range of international and national rock and metal acts. The festival takes place in August and has featured artists such as Iron Maiden, Ozzy Osbourne, and Metallica.

5. Rototom Sunsplash: This reggae music festival takes place in the town of Benicàssim, and features a range of international and national reggae and dancehall acts, as well as DJ sets and other performances. The festival takes place in August and has featured artists such as Bob Marley, Damien Marley, and Shaggy.

Overall, the region of Castellón and the surrounding area host a number of music festivals that offer a range of genres and styles and attract a diverse range of performers and audiences.