The Church of All Saints on Portland has been added to Historic England's Heritage At Risk Register, along with five other sites in the south west region.

The church dates back to the early 20th century, when Portland's rector expressed a desire for a new building to be constructed to replace St George's as Tophill's parish church.

Fundraising took place for several years and in 1914 construction begun, with the foundation stone laid weeks before the outbreak of the First World War. Building continued regardless and the church opened to worshippers in 1917.

Built of Portland ashlar with tiled roofs, to the design of Crickmay and Sons, Historic England have now defined the grade II listed place of workshop as in poor condition, with slow decay and no solution agreed.

An ancient barrow in Purbeck is also amongst the new additions to the register. Dating back to the Bronze Age, the late Neolithic funeral monument is located at North Hill, north east of Renscombe Farm in Worth Matravers.

It has been included as an archaeological site threatened by arable ploughing, with extensive and significant problems. Thought to have been constructed between 2400 and 1500BC, the bowl barrow has a mound of earth and limestone blocks measuring 25m in diameter.

A spokesperson from Historic England said: "The barrow lies within an extensive area of field system which is likely to have prehistoric origins. However, this has been reduced by ploughing to the extent that only fragmented remains will survive."

The four other Dorset monuments listed as at risk include: the castle hillfort at Cattistock; the round barrow on Dickley Hill in Cerne Abbas; the settlement on Dickley Hill; and High Cank, a hengi-form monument in Up Cerne.

The Heritage At Risk Register includes historic buildings and sites at risk of being lost through neglect or deterioration. Historic England works with owners, friends groups, developers and other stakeholders to find solutions for preserving the places in greatest need.

Across the UK there are 748 grade I and II listed buildings, excluding places of worship, on the At Risk Register, including 148 in the south west region. Buildings or structures are removed from the register when they are fully repaired and their future secured.