The Spectacius tomb is 8 metres high and is the highest tomb in Šempeter. Gaius Spectatius Finitus, mayor of Celeia, had the tomb constructed for himself, his son Gaius Spectatius Priscianus and probably for his wife too. The exact date of tomb’s manufacture cannot be ascertained, however, it is presumed that it dates back to the reign of Marcus Aurelius (161–180) or Septimius Severus (193–211).
Many reliefs adorn the tomb, each telling its own story. The bottom reliefsdepict the story of Iphigenia. Motifs of four seasons and images of the twins Castor and Pollux depicted in the corner reliefs supplement the rich decoration of the ash container. The tympanum depicts a struggle among animals and holds a tablet where names of the buried are inscribed. Under the roof of the tomb, statues of the three family members are displayed. On the top of the roof, a head of Medusa is facing forward, guarding the resting place of the dead.