Caerphilly Castle towers rise from ruins in CGI

Video caption, Long-missing sections of Caerphilly Castle have been re-created

Wales' largest castle has had its fair share of strife and wear and tear over the centuries but it is now being rebuilt - thanks to CGI technology.

You can watch Caerphilly Castle as it would have looked in the early 14th Century, when it stood up to an attack by 10,000 Welsh rebels.

Historic monuments body Cadw is using the latest video technology to show the castle being reconstructed.

It is the first in a series to re-imagine how historic sites once looked.

The video captures the "walls within walls" system of defence that was favoured by Gilbert de Clare, the Norman nobleman responsible for building the castle in 1268.

Sections of the old castle, now long gone, rise from the ground while the leaning south-east tower - thanks to the magic of computer graphics - straightens and returns to its former glory.

Tony Payne, castle custodian, said: ""It's about bringing the castle to life.

"It's a new concept we've not used before. I can see it will attract a different audience, a generation used to computer gaming.

Image caption, Senior animator Chris Marshall working on the project

"When we've had reconstruction drawings, they're fantastic, but with the video you can go on a journey."

Animator Chris Marshall said it was a matter of joining the dots of what was there now and research into how the castle would have looked.

"There were multiple challenges - the first thing is we have to make sure it's as historical accurate as possible," he said.

"My first task was to go to the castle to do my own research, and then we asked the experts to provide whatever information they could, including illustrative interpretations of what they believed it would have looked like when built."

Image source, Cadw

Image caption, Caerphilly Castle - complete again

'Easy to pick up'

He said the software he used now was similar to the sort people could download for free at home on their own PCs.

"There's nothing holding anybody back - this was very much a specialist field 10 or 15 years ago.

"To work in this industry you'd needed expensive software and hardware and fairly sophisticated technical skills but the technology has moved on.

"The 3D animation software now means the tools are easy to pick up at a fairly basic level. To create a building and an animated camera flying through it is within the realms of most people at home today."

The castle has been used as the backdrop to TV programmes including Doctor Who and Merlin.