text: Steep stairs to the right of the main entrance lead to the small Museo Marciano , where you can see the original four tethered bronze horses , dating from the 2nd or 3rd century a.d. and a privileged close-up of the basilica 's mosaic ceilings from the museum 's open galleries .
  
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  The bronze horses date from the 2nd or 1st century B.C.