Two historic Scottish buildings have been added to a list of the world's 100 most endangered places, it was announced yesterday.

An 18th-century mansion in Midlothian and a derelict post-war seminary near Dumbarton were listed alongside buildings ruined by the conflict in Iraq, the Peruvian Inca city of Machu Picchu, and New Orleans by the World Monuments Fund (WMF).

The WMF publishes an annual "watch list" of the most threatened of the world's heritage sites.

New Orleans, which was devastated by Hurricane Katrina, was added because it faces the likelihood of stronger storms in the future, while Machu Picchu is threatened by tourism.

Mavisbank House in Midlothian is one of the finest examples of neo-classical architecture in Scotland, but was partially destroyed and left in ruin by a fire in 1973.

Roofless and exposed to the elements, the shell of the building, listed as category A by Historic Scotland, is in an advanced state of deterioration, with the remaining exterior walls compromised by water ingress and vegetation.

"It is hoped that listing will expedite the restoration of this architecturally significant structure," a spokesman for the WMF said.

St Peter's College, in Cardross, near Dumbarton, was named Scotland's greatest post-war building by architecture magazine Prospect.

It has been subject to vandalism and decay, the Archdiocese of Glasgow has done little to maintain or protect the site, and in 2004 lodged an application to consolidate the buildings as a ruin, according to the WMF.

Bonnie Burnham, WMF president, said: "On this list, man is indeed the real enemy. But, just as we caused the damage in the first place, we have the power to repair it, by taking our responsibility as caretakers of the world's cultural heritage seriously.

"So we are sounding the alarm, using the World Monuments Watch List to demonstrate the importance of working together to meet these challenges and join forces to protect our world's shared architectural heritage."

The other UK and Irish sites on the list were: Richhill House, Armagh City, Northern Ireland; Wilton's Music Hall, the last remaining example of a mid-Victorian London music hall; Vernon Mount, a Neo-classical suburban villa in Cork; and Tara Hill, a sacred landscape at the heart of Ireland threatened by a motorway.