Complex sentence: Boxwood triptychs could be incredibly intrinsic and complex, a triptych altarpiece (MMA 17.190.453) in the Metropolitan Museum of Art contains a receptacle for holding relics.
Split into simpler sentences: Boxwood triptychs could be incredibly intrinsic and complex. A triptych altarpiece (MMA 17.190.453) in the Metropolitan Museum of Art contains a receptacle for holding relics.