ancient artificial bare.bleak barren cliff desert dry escarpment exercise harsh historical Israel landscape Massada old rock rocky roman sere siege slope tour group tourism tourists walk line trail Trek advice alert announcement appropriate-behavior appropriate-behaviour aware awareness black care careful caution communicating communication considerate consideration danger directions fence informing lettering letters red sign signs warning white wording words abstract background barrier bolders boulders color colour constructed cover covered fitted fitting large limestone local-stone mortar mound perspectives random randomly-coursed retaining-rocks rocks rough rugged secure security shade shadows shaped shapes sharp solid stone stone-walled stones stonework strength strong sunlight sunshine surface surfaced surfaces texture textures uneven variations variety