Buildings from across the ages attract thousands of visitors

Firefighters were called to the blaze in a 19th century slate hay shed at the Museum of Welsh Life at St Fagans near Cardiff just after 2100 BST on Friday evening.

South Wales Police and fire officers are still investigating the cause of the fire but they believe arsonists were to blame.

The museum will remain open to visitors despite the incident.

The open-sided barn - which was full of hay at the time of the fire - was built in 1870 and was acquired by the museum in 1977. The roof is made of slate, as are the slate pillars which support it.

The slate comes from the Maentwrog, near Porthmadog, in north Wales and the building is one fo the last remaining in Wales.

Free admission has boosted visitor numbers

John Williams-Davies said the roof had been completely destroyed and other parts would need extensive repairs.

"The fire didn't warrant closing the park, but it's a blow to the building heritage of Wales," he said.

Craftsmen from the museum will travel to north Wales on Monday to search for replacement slate. Repair work will start as soon as possible, though it will mean other building projects will have to be postponed.

Firefighters have been monitoring the scene and crews will return to the shed throughout the weekend to ensure the fire does not re-ignite in the hot weather.

Youths fled

A security guard on patrol saw two to three youths in the museum grounds after it had closed on Friday.

It is thought they climbed over the security fence. The guard said they fled when disturbed, but must have returned later and started the fire.

The St Fagans site has established itself as one of Europe's foremost open-air, "living history" museums, and ranks as one of the most popular heritage attractions in Wales.

Traditional buildings from all over Wales have been moved to the site, re-assembled and furnished with authentic pieces.

The collection includes a school, a chapel, a workmen's Institute, cottages, and agricultural buildings, and a police station.

The museum hosts cultural events and fairs

Last year the site was voted the top free-admission attraction in Wales, after pulling in more than 600,000 visitors.

Now one of the National Museums and Galleries of Wales, the Museum of Welsh Life opened in 1948.

The museum's aim is to demonstrate how the people of Wales lived, worked and spent their leisure time during the past 500 years.

It stands in the grounds of the magnificent St Fagans Castle, a late 16th century manor house donated to the people of Wales by the Earl of Plymouth.

The 100-acre parkland now has more than 30 original buildings.

Craftsmen like blacksmiths and coopers provide working demonstrations in traditional costume, and there is a working bakery on site which sells fresh bread and cakes made to traditional Welsh recipes.

Native breeds of livestock can be seen in the fields and farmyards, and regular demonstrations of farming tasks take place daily.