3 ▁and ▁is ▁the ▁only ▁tram way ▁line ▁to ▁remain ▁in ▁service ▁during ▁the ▁later ▁part ▁of ▁the ▁tw enti eth ▁century . ▁Line ▁ 6 8 ▁stretch ed ▁from ▁No a illes ▁to ▁Al h amb ra , ▁serving ▁La ▁Pla ine , ▁the ▁Bou lev ard ▁Ch ave , ▁the ▁La ▁Blan car de ▁railway ▁station ▁and ▁Saint - Pierre ▁c emetery . ▁The ▁central ▁termin us ▁is ▁situated ▁in ▁a ▁tunnel . ▁This ▁tunnel , ▁built ▁in ▁ 1 8 9 3 , ▁is ▁unique ▁in ▁France ▁and ▁was ▁built ▁to ▁give ▁access ▁to ▁the ▁city ▁centre , ▁avoid ing ▁the ▁narrow ▁streets ▁of ▁some ▁of ▁Marse illes ' s ▁sub ur bs . ▁Because ▁of ▁the ▁problems ▁involved ▁in ▁converting ▁the ▁line ▁to ▁bus ▁use ▁it ▁was ▁decided ▁to ▁keep ▁the ▁line ▁oper ational . ▁ ▁Line ▁ 6 8 ▁is ▁ 3   km ▁long ▁and ▁it ▁remained ▁out ▁of ▁use ▁until ▁ 1 9 6 5 ▁when ▁it ▁was ▁decided ▁to ▁modern ise ▁it . ▁Line ▁ 6 8 ▁was ▁modern ised ▁in ▁ 1 9 6 9 ▁with ▁the ▁introduction ▁of ▁twenty - one ▁P CC ▁tram c ars ▁and ▁the ▁whole ▁track ▁was ▁rela id . ▁The ▁first ▁of ▁the ▁P CC ▁cars ▁arrived ▁on ▁ 2 6 ▁December ▁ 1 9 6 8 ▁and ▁the ▁first ▁tram ▁went ▁into ▁service ▁on ▁ 2 0 ▁February ▁ 1 9 6 9 . ▁The ▁last ▁of ▁the ▁old ▁tram c ars ▁was ▁with dra wn ▁that