Under the Ancient Monuments and Archaeological Areas Act 1979, the Welsh Ministers, through Cadw, compile a Schedule of Ancient Monuments. The monuments included on the Schedule are of national importance and cover a range of archaeological sites.
Some examples may be completely buried below ground, and may only be known through archaeological excavation. Others are far more prominent, and include the ruins of medieval castles and abbeys. Scheduled monuments are often in a ruinous or semi-ruinous condition or take the form of earthworks. The Welsh Government’s criteria for scheduling ancient monuments can be found on the CADW web site.
Any proposal to carry out works at a scheduled ancient monument which would have the effect of demolishing, destroying, damaging, removing, repairing, altering, adding to, flooding, or covering up a monument must obtain scheduled monument consent. It is an offence to carry out such works at the site of a scheduled ancient monument without first obtaining scheduled monument consent.
Under the terms of the Ancient Monuments (Class Consents) Order 1994, certain works are deemed to enjoy scheduled monument consent. Primarily, they cover agricultural, horticultural and forestry work of the same kind as has been carried out at the monument over the preceding six years (with certain exceptions). Other works include those carried out by certain major organisations, works for health and safety, archaeological evaluations, and works which are being grant-aided by Cadw.