The song "Cuatro Viajes" by Mateo & Cabrera is about a journey to the moon. The lyrics describe the discovery of two flags on the moon and the colorful breeze that was noticed there. The song talks about four trips made to the moon and how no one has traveled there since. It reflects on the mystery and beauty of the moon and the experience of traveling to such a distant and unknown place. Overall, the song explores themes of exploration, discovery, and the unknown.