We've been visiting Mallorca for years. Going again this year. We were in Valencia a couple of weeks ago. It's a lovely city with sandy beaches. For a longer lazy holiday I would prefer Mallorca but for two days as part of a longer trip I would recommend Valencia.
There is much more to see in Valencia than Mallorca.
Downtown Valencia is the Plaza del Ayuntamiento. The main shopping area is here, together with many restaurants. If one stays near this place, most of the city center is walkable. Use Booking.com to screen hotels and apartments. In the District box, choose Ciutat Vella, Eixample or Extramurs.
1. Oceanographic (the best aquarium in Spain)
2. Bioparc (one of the best zoos in Spain)
3. Cathedral and Basilica of the Virgin of the Helpless
4. City of Arts and Sciences
5. Silk Exchange - La Lonja de la Seda
6. Palacio del Marques de Dos Aguas
7. Bellas Artes Museum
1. Restaurante Navarro Valencia (Calle del Arzobispo Mayoral, 5 – Tel: 963-529-623) is one of the best restaurants downtown. However you need a reservation because it is so popular.
2. Casa Roberto (Calle Maestro Gozalbo, 19 - Tel: 963-951-361).