A Bronze Age sauna and one of the oldest prehistoric roundhouses in the UK have been unearthed on a Taunton site earmarked for a park-and-ride scheme.

Archaeologists have uncovered 3,000 years of history at the site near the junction of the A358 and the M5 at Cambria Farm.  The Iron Age roundhouse with a diameter of 56ft (17m) is one of the largest prehistoric roundhouses ever found in Britain.

It is thought to date from around 700BC and has been uncovered alongside three other roundhouses.

A mound of burned stones indicating a 2,500-year-old sauna has also been discovered as well as the remains of a Roman farm.  A number of skeletons, all but one Roman, have also been unearthed after archaeologists spent more than three months on site.

Other finds have included a pair of Roman shears, three Iron Age spearheads, loom weights and Roman brooches, as well as large amounts of pottery.

Steven Membury, historic environment officer at Somerset County Council, said: "The idea that the stone indicate 'sweat houses' is just one theory.

"We can tell that the huge roundhouse burned down but we think we have one surviving post which we will be able to carbon date."