Complex sentence: The walls of the outer lobby are built from huge unadorned blocks with a fake sandstone surface, with only the front of the ticket box office decorated in a dusky sienna red with a golden sunburst emblazoned above the window.
Split into simpler sentences: The walls of the outer lobby are built from huge unadorned blocks with a faux sandstone surface. The front of the ticket box office is decorated in a dusky sienna red with a golden sunburst emblazoned above the window.