david mccullough bridge, or sixteenth street bridge, strip district, pittsburgh, from beneath with clear blue sky

america contrast david mccullough dramatic historic iconic light metal north outdoors pattern pennsylvania pittsburgh shadow steel strip district summer sunny symmetry tourism travel usa united states urban abstract allegheny county architecture blue sky bridge city life cityscape clear commercial creative engineering explore geometric hdr hidden gem high dynamic range industrial infrastructure landmark metropolis perspective sixteenth street transportation underbridge unique angle viewpoint