Cardiffian Thomas, 21, was the youngest rider on the Tour

"It's been tough, I enjoyed the sprints but as soon as we hit the Alps it was a different kettle of fish," said Thomas, at 21 the youngest rider on the Tour.

"Everyone dreams of riding down the Champs-Elysee and finishing the Tour, I'm happy to get here but feeling it."

Thomas finished 140th, nearly four hours behind winner Alberto Contador.

606: DEBATE Your thoughts on Thomas's achievement

He was 133rd on the final day's racing into the heart of Paris, 51 seconds behind stage winner Daniele Bennati.

Wim Vansevenant was the only rider to finish behind Thomas, earning the Belgian the 'lanterne rouge', but getting to the end was the real achievement for the Welshman.

Many expected the Barloworld rider to gain some early experience then pull out when the Tour hit the punishing mountain stages, but Thomas said that was never in his thinking.

"I was always going to go as far as I could," said the Cardiff man, who is the youngest Briton to finish the Tour.

"I couldn't see the point in going home after a few days, it was always in my mind to try to finish and it's awesome to be at the end.

When we got to the mountains I was just trying to survive Geraint Thomas

"I couldn't imagine what it would be like before, but I wanted to get stuck in and see what it was all about, I don't think you can imagine how hard, fast and chaotic it is out there until you actually do it.

"When we got to the mountains I was just trying to survive, taking it day by day.

"Now I want to go out, have a few beers and catch up with some friends, but I will definitely be resting for a few weeks. Going to bed is the main aim!"

Thomas said he did not want to focus on the drug problems that blighted the Tour, but he feels that something good may come from the scandals.

"It's obviously not been great, but times and attitudes are slowly changing," the 2004 World Junior Track Championships gold medallist told BBC Sport Wales.

"It's good for the future that people are getting caught now.

"It's annoying that experienced riders need to cheat because I'm a first-year pro and I've managed to get around.