There’s long been speculation of underground chambers below the monument known as the Khaznah, or the Treasury, in the ancient city of Petra, Jordan — and now it’s been confirmed. Archaeologists recently discovered a tomb with at least 12 human skeletons and artifacts, estimated to be at least 2,000 years old, CNN reported. The elaborate monument, carved into pink sandstone cliffs, has been featured in several movies — it’s most well-known as the site of the Holy Grail in the 1989 film “Indiana Jones and the Last Crusade.” In 2003, two tombs were found below the left side of the...