You find the shield of Bigastro on all official documents and elsewhere.
The design is simple; the left hand side represents Aragon and the right the river Segura. the bridge and windmill that symbolise the town. On top is a Ducal crown.
Its use dates back to 1975 when the mayor of Bigastro, Jose Navarro Guillen, authorised it prior to the fiesta for San Joaquin.