Located in Southern England, what massive work of art is carved into the side of a hill?

I know I've seen it!! truly magnificent.

There's a White Horse at Sutton, North Yorkshire, but it's not ancient! It was created by a geography, or maybe history, teacher and his pupils. Not sure how old it actually is but I'm 66 now and it's been there as long as I can remember.

I hadn't realised that the white horse was so old.

robertthemoose14, There are several white horses in England. I've walked around the one in Westbury, Wiltshire. it's huge.

Something to see...from a train one can get a good view.

FunkyMonkey, doesn't count, since it isn't man-made..

the duck was an April fools joke