Excavations at a Roman site have revealed the "Pompeii of the north", delighted archaeologists said.
The spectacular discoveries at Binchester Roman Fort near Bishop Auckland, County Durham, date back some 1,800 years and include one of the earliest pieces of evidence for Christianity in Roman Britain in the shape of a silver ring.
The archaeologists have discovered a bath house with seven-foot high walls, which were once covered with brightly-painted designs, and the original floor, doorways and window openings.
An inscribed altar dedicated to the Roman Goddess Fortune the Home-bringer, has also been unearthed.
Dr David Mason, principal archaeologist for Durham County Council, said: "These findings are hugely significant as they are virtually intact and present a graphic illustration of life under the Roman Empire.
"They are so stunning and spectacular that we can claim we have our very own 'Pompeii of the north' right on our doorstep."
A joint project to explore the site between the county council, Durham University, local enthusiasts and Amercian university students, is now in its sixth year.
Last year Alex Kirton, 20, from Hertfordshire, discovered a carved sandstone head at Binchester, which was believed to be a Geordie Roman god that probably was worshipped locally.
Project coordinator, Dr David Petts, lecturer in archaeology at Durham University, said: "Our excavations have uncovered parts of one of the best preserved Roman buildings in Britain.
"The building itself and the wonderful array of artefacts we have recovered from Binchester give us an unparalleled opportunity to better understand life on the northern frontier in the Roman period.
"For example, the altar is a reminder that bath houses were about more than keeping clean and exercising and were actually social centres - a bit like our modern day leisure centres.
"The most unique feature of these remains is the sheer scale of their preservation.
"It is possible to walk through a series of Roman rooms with walls all above head height; this is pretty exceptional for Roman Britain."
The altar has been inscribed by a retired trooper who served with a unit of the Spanish cavalry based at Binchester.
The trooper described his rank as "architectus" and this is the only example from the whole of the Roman Empire, outside of Rome itself, which shows that architects were on the staff of auxiliary cavalry units and not just the legions of the Emperor's personal protection unit, the Praetorian Guard.
The findings coincide with the Binchester Roman Festival this weekend featuring guided tours of the recent excavations.
The festival also features several re-enactment groups.
Binchester, which stands near the River Wear, was known to the Romans as Vinovia and commanded the main road that ran from the legionary headquarters at York north to Hadrian's Wall.
It formed a key element of the complex frontier system that lay both sides of the Wall which marked the northern-most edge of the Roman Empire for nearly 400 years.