Archaeologists are hoping to shed more light on the origins of a 13th Century castle in mid Wales.
Montgomery castle was demolished in 1649
Historic monuments agency Cadw has started a week-long dig at Montgomery Castle to reveal more of its medieval entrance, known as the gatehouse.
Over the centuries earth has covered its lower sections, but Cadw hopes to reveal the base of it.
Archaeologists have investigated the castle site for decades, but this is the first dig since the mid 1980s.
The castle was built in about 1224 by Henry III.
It later survived attacks by Welsh noblemen Llywelyn ap Iorwerth in 1228, and 1231, and by Dafydd ap Llywelyn in 1245.
The castle was built on a hill in Montgomery
It last saw action under the Herbert family during the English Civil War, when it surrendered to the Parliamentarians in 1644.
Five years later it was demolished, along with a mansion built nearby.
Sian Rees, Cadw's inspector of ancient monuments in the area, said the castle dated back to the 13th Century.
She said she hoped to find the foot of the gatehouse under part of a demolished mansion built by the Herbert family.
During the dig, which started on Monday, access to the castle via the gatehouse will be restricted until 4 May.
Work to install a new footbridge to improve disabled access is also being carried out.
A spokesman for Cadw said: "While it will still be possible to access the monument by other routes some are not ideal for disabled visitors."