. ▁It ▁includes ▁an ▁extensive ▁system ▁of ▁est u aries ▁and ▁can als ▁which ▁flow ▁a ▁dich a ▁r ia . ▁To ▁the ▁west ▁they ▁are ▁limited ▁by ▁the ▁town ▁of ▁Ay am onte ▁and ▁by ▁the ▁S ap al ▁Nature ▁Reserve ▁of ▁Castro ▁Mar im ▁and ▁V ila ▁Real ▁de ▁Santo ▁Ant ón io ▁( bel ong ing ▁to ▁the ▁Gu ad iana ▁river ). ▁To ▁the ▁north ▁the ▁V ía ▁Ver de ▁L itor al ▁road , ▁to ▁the ▁south ▁Is la ▁Crist ina ▁city ▁and ▁the ▁Atlantic ▁Ocean ▁and ▁an ▁area ▁of ▁Mediter rane an ▁p ine ▁forest ▁and ▁d unes ▁of ▁I CON A ▁( Inst ituto ▁para ▁la ▁Con ser va ción ▁de ▁la ▁Natur ale za ) ▁and ▁finally ▁to ▁the ▁east ▁an ▁area ▁close ▁to ▁the ▁heart ▁of ▁the ▁Red ond ela . ▁ ▁The ▁d rain age ▁and ▁import ▁of ▁water ▁come ▁essentially ▁from ▁the ▁Atlantic ▁Ocean . ▁The ▁Gu ad iana ▁river ▁brings ▁sed iments ▁and ▁maintain s ▁the ▁integrity ▁of ▁the ▁can als ▁in ▁the ▁Is la ▁Crist ina ▁mar sh es . ▁ ▁Con sequently , ▁there ▁are ▁different ▁degrees ▁of ▁sal inity ▁among ▁the ▁mar sh es . ▁Some ▁parts ▁of ▁the ▁mar sh es ▁can ▁be ▁and ▁are ▁commer cially ▁explo ited ▁to ▁extract ▁salt . ▁ ▁It ▁is ▁a ▁place ▁where ▁the ▁litt oral ▁and ▁sed iments ▁dynamics ▁have ▁triggered ▁a ▁whole ▁complex ▁of ▁coast al ▁form ations ▁in ▁the ▁mouth ▁of ▁the ▁Gu ad iana ▁river ▁est u