coast dry Malta rock rocky ancient city europe history ocean sea town Valetta architecture building compact dense homes houses Three Cities urban water boats ferry Gozo harbour landscape abstract Amalfi-cross angles appearance aspirations background care christian compassion cross eight-pointed emblem emblematic hospital hospitallers knights Knights-Hospitaller Knights-of-Malta light maltese Maltese-cross obligations service stained-glass symbol symbolic window community flower hill mediterranean plant rural sky spring view village yellow bell facade fortifications historical Holy places old sandstone stone tower drystone elements wall Dwejra Dwejra bay rocks