The Catacombs of San Callisto are an ancient burial site located on the outskirts of Rome, Italy. Dating back to the 2nd century AD, these catacombs served as a resting place for early Christians and are one of the largest and most important in the city. They feature a complex network of tunnels and chambers, showcasing early Christian art and inscriptions. Visitors can explore the catacombs, which contain the graves of numerous martyrs and popes, including Pope Cornelius. The site reflects the early Christian community's practices and beliefs, providing valuable insights into their history and culture.