Oppidum des Châteliers, Archaeological site in Amboise, France.

The Oppidum des Châteliers is an archaeological site spread across a limestone plateau with visible remains of temples, homes, and craft workshops from ancient times. The location sits elevated overlooking where two rivers meet, creating natural defensive advantages still marked by ancient rampart systems.

The plateau was permanently settled in the Neolithic, when a 230 m rampart with an outer ditch enclosed about 8 ha at the tip where Amboise castle now stands; a deposit of weapons, ornaments and parade chariot pieces was found at its southern end. At the end of the Iron Age the oppidum expanded east over more than 50 ha, with a new rampart rebuilt until about 70 BC, and may have been the Turones' capital under the name Ambacia. Amboise tradition places Caesar's camp here after the siege of Avaricum in 52 BC, though no archaeology confirms it.

The name Ambacia, recorded by Sulpicius Severus as Ambaciensis vicus, likely comes from the Gallic ambe, meaning near water, fitting the spur above the Loire and Amasse. At least three Iron Age and Roman fana stood here, and pottery, weaving, metallurgy and woodworking workshops have been excavated.

The site is accessible but some rampart structures are faint and partly on private land that may limit exploration in certain areas. It helps to walk slowly across the plateau and watch for ground irregularities that reveal traces of ancient buildings and fortifications.

The Butte de César, at the exact centre of the plateau, was named only in the 19th century; it may be a funerary tumulus of the 5th century BC, and it lies well east of the first Neolithic or Bronze Age rampart, not inside it. The 800 m earthen rampart that closes the spur stands at the eastern edge of the site.