approach flower landscapes Mexico monolith sky stone canyon cliffs colorado erosion grand junction monoliths monument plain plateau red rock formation rocks rugged usa vertical view attraction Gran Canaria island landscape mountain rock Spain stones sundland ancient avebury England english Great Britain historical menhir neolithic old pillar West Kennet Avenue wiltshire lichens architecture bridge cables California Golden Gate landmark ocean rivets rusted San Francisco steel structure symbol tall tower age background blue brick brickwork building castle constuction Greek houses light residential traditional urban window