▁was ▁opened ▁in ▁ 1 8 4 8 ▁and ▁the ▁second ▁in ▁ 1 8 7 8 . ▁ ▁The ▁Ar ri aga ▁Theater , ▁the ▁Ar en al ▁de ▁Bil ba o ▁( B il ba o ▁Ar en al ) ▁park , ▁the ▁Est ación ▁de ▁Con cord ia ▁( Con cord ia ▁Train ▁Station ) ▁and ▁the ▁B ail én ▁Sk ys cra per ▁( the ▁first ▁sk ys cra per ▁of ▁the ▁city ) ▁can ▁be ▁seen ▁from ▁the ▁bridge . ▁ ▁History ▁▁ ▁Al ong ▁with ▁the ▁growth ▁of ▁Bil ba o , ▁the ▁urban ▁centre ▁of ▁the ▁city ▁expanded ▁beyond ▁the ▁old ▁original ▁seven ▁streets , ▁and ▁started ▁to ▁expand ▁over ▁territ ories ▁of ▁the , ▁by ▁that ▁time , ▁el iz ate ▁of ▁Ab ando . ▁In ▁fact , ▁the ▁trans it ▁of ▁people ▁moving ▁from ▁Ab ando ▁to ▁Bil ba o ▁or ▁from ▁Bil ba o ▁to ▁Ab ando ▁grew ▁every ▁year ▁and ▁became ▁more ▁fluid . ▁As ▁the ▁only ▁bridge ▁that ▁crossed ▁the ▁Est u ary ▁of ▁Bil ba o ▁was ▁the ▁San ▁Ant ón ▁Bridge , ▁it ▁became ▁a ▁necessity ▁and ▁a ▁priority ▁to ▁build ▁a ▁new ▁bridge ▁that ▁would ▁connect ▁both ▁banks ▁of ▁the ▁river . ▁ ▁Iron ▁Bridge ▁( 1 8 4 5 ▁- ▁ 1 8 7 6 ) ▁▁ ▁The ▁bridge ▁project ▁was ▁introduced ▁in ▁ 1 8 4 4 , ▁and ▁it ▁was ▁built ▁during ▁ 1 8 4 5 , ▁to ▁be ▁finally ▁opened ▁in ▁ 1