Tradução de "Step - He discovered a step that had...''

Olá. Fiquei com dúvida sobre o que o autor quis dizer nesse texto com o uso da palavra step e stairs

Carter became obsessed with finding the tomb of the forgotten dead king. His patience paid off. On November 4th, 1922, he discovered a step that had been cut into a rock. The step led to 16 stairs. The stairs led to a sealed door covered in royal designs.

Minha dúvida é: ele encontrou um degrau que levava à 16 escadas ou a 16 outros degraus?
O contexto é a descoberta do túmulo de Tutankamon