-If we superimpose one on the other... -Wow, look at that.

-youve got clearly a circular building coming 'round like that.

So, there's the post holes, 'round there, 'round there, 'round there, 'round there, 'round there.

And then, actually, just back 'round there.

So, we've got a massive buil what's that, 30 meters across?

-It's a 30-meter grid, yeah.

And it's not right in the middle, is it?

No.

It's actually slightly t one side, which is interesting.

-Thats right, and you can see how they fitted it in Yeah.

tightly, into the southwest corner of the amphitheater, and doubl post holes all the way 'round.

One-two, one-two, one-two, one-two.

Huge, great big Yes, a large structure, isn't it?

Yeah.

monumental building there.

Isn't that amazing?

-The post holes are significant, arent they Yeah.

in terms of, you know, the posts are there, how tall could it have been?

-Could be taller than the amphitheater itself... =Couldve been, yeah.

- with, presumably, a circular, big, pitched conical roof.

-Mark's new results show how the amphitheater, left by the Romans, was added to.

The massive structure was fortified to be used as a stronghold.

A newly discovered, round timber buildin sits at one end of the fortress.

Mark believes it's from around the time of Arthur.

-It's just staggering to think of the scale of what must have been there in the 5th century.

A huge circular building occupying the whole of the southwestern part of the amphitheater.

What was the function of this building?

Well, you know, it can only have been for political or military reasons.

-Could this massive round building inside a fortress be where a military leader who becomes known as King Arthur, gathered his forces together?

Many modern scholars have suggested that medieval romance writers took the fol memory of a round assembly place and invented the idea of the Round Table.

But no one was aware of the structure hidden here.

-I think this place is where the idea of the Round Table had its genesis.

Either the oval amphitheater, or the circular gigantic building that we found sat within it, and that we're standing looking at the place where the post-Roman militia, the Arthurian army, gathered before literally riding out to defend what was left of Roman Britain.