Hi Trisha
I'm not too sure of the dates but 2 of the festivals we have attended are:
1. Feastival of St John, this takes place in Alicante and there are lots of temporary bars and lots of really large "papier mache" statues which get set on fire at midnight. We heard the call "agua, agua" and as we got closer the local fire service drenched the willing participants as a baptism! Fantastic night, We stayed overnight in Alicante and the next morning when we got up everything was cleaned up as if nothing happened!
2. Roman festival in Cartagena. The Romans come ashore from a boat which docks in the port and then a huge procession takes place all the way up the main street. The different people from slaves to "Ceaser" and his aids all walk up the street. Different fighting legions walk up the street and give out food, drink, chocolate coins (to pay your taxes) and a huge man drawn catapult which fires a bucket of sweets for the children in the crowd to pick up.
These are two very enjoyable events and we recommend you get there early for parking and to see how the day builds up to the finale.
Hope this is useful
Regards
Nigel & Stella