De locis sanctis (Concerning sacred places) was composed by the Irish monk Adomnán, a copy being presented to King Aldfrith of Northumbria in 698. It was based on an account by the Gaulish monk Arculf of his travels to the Holy Land, from which Adomnán, with aid from some further sources, was able to produce a descriptive work in three books, dealing with Jerusalem, Bethlehem, and other places in Palestine, and briefly with Alexandria and Constantinople, called De locis sanctis ("Concerning the sacred places"). It aimed to give a faithful account of what Arculf actually saw during his journey.
The first book of Adomnán's transcription concerns what Arculf saw during nine months he spent in Jerusalem ca 680, beginning with useful descriptions of "the Sepulchre of the Lord and the Church constructed over it, the form of which Arculf himself depicted for me on a tablet covered with wax" and mentioning the Basilica of Constantine and other features such as the column that marked the center of the earth. Arculf also saw many relics such as the miraculous grave cloth of Jesus (compare the Shroud of Turin), which had brought generations of good fortune, and the very fig tree on which Judas Iscariot hanged himself. Arculf saw the Basilica of Mount Sion, Mount Olivet and the Tomb of Lazarus at Bethany. Everywhere Arculf's description attests to the flocks of pilgrims in the Christian holy places.
The second book begins with Arculf's trip to Bethlehem and the church dedicated to Saint Mary over the half-cave of the Nativity, the simple churches, one containing the tomb of King David another of Saint Jerome and even those of the shepherds who were present at the Nativity. Arculf visited the tomb of Rachel, six miles west of Jerusalem. Brief mention is then made of the ruins of Hebron and of Jericho and the Sepulchre of Arba's tombs of the four patriarchs (Abraham, Isaac, Jacob, and Adam), and the oak of Abraham. Arculf next refers to Galgal and the church containing Twelve Stones of the tribes of Israel. The journey then picks up along the Jordan where Arculf saw the place where John baptized Christ as well as the small church located at the spot where Jesus left his clothes while the baptism took place. Nearby was a monastery and a church built in honor of John the Baptist. Arculf saw the Dead Sea and the sources of the Jordan, two adjacent springs, named "Jor" and "Dan", the Sea of Galilee and the well of Samaria, where the Lord met the Samaritan woman. At Nazareth he visited the Church of the Annunciation. Mount Tabor in Galilee is next in the narrative. Arculf's guide, a certain Peter, a Burgundian hermit, would allow him to tarry no longer than necessary "…for a rapid inspection." Arculf continues with brief allusions to the cities of Damascus and Tyre, then he left Jerusalem and traveled forty days to reach Alexandria, where was the church containing the tomb of the Evangelist Mark.