Valencia is around about 1 hours drive from Javea. It is a beautiful city with some fantastic architecture and the cathedral that famously holds the holy grail. This is subject to much debate as the chalice they have is very ornate and gold, where as they holy grail is believed to be very humble. You can make up your own mind.
There is much to do in Valencia, you can drive from Javea and park in one of many underground car parks or if you don’t want to drive in a city you can catch a train from Xeraco, about 45 minutes drive from Javea and it has easy free parking. The train takes you to the central station bang in the middle of town.
There are several areas to Valencia. The old part of town where the Cathedral is and many narrow streets. The Colon shopping area, this is close to the Central station and has a large selection of shops from department stores to luxury boutiques. Then you have the arts and Sciences centre with the aquarium and other tourist attractions.
Valencia also has a beach area with a long stretch of beach as well as shipping port. On the outskirts there is an IKEA which is great if you are buying a house here.