The lone tourist standing next to me, an Australian girl, can stand it no longer.

She grins, then breaks the silence with a snigger, shooting looks at her partner back in the car park before retreating. I share her amusement and embarrassment. It's hard to be solemn when staring at the Cerne Abbas Giant, who sports an erection that would shame a whale: it's eight metres long. How polite Britain's other chalk figures seem in comparison.

The Long Man of Wilmington in Sussex is all arms and legs, although vandals did draw a penis on him in 2002. The various white horses scattered around the country look like mares.

Quite why the hunk under scrutiny came to be etched into a Dorset hill in western England nobody knows. According to one theory, primitive men carved it to give the gods something to look at, although you might think the gods had better things to do.

Maybe the figure represents Hercules, or a giant who once terrorised local inhabitants. Supposedly, the giant was attacked and killed when he fell asleep on the hill, and his erstwhile victims drew a chalk line around him, just as police outline the position of bodies today.

But it could be that the he-man owes his existence to a real, larger-than-life individual: Oliver Cromwell, the general who overthrew Charles I and governed England as Lord Protector from 1653 until his death five years later. According to Dorset scholar J.H. Bettey, a baron who loathed Cromwell created the figure as a mockery. The 37-metre club, a military reference, that the giant grips in his right hand seems to support that theory.

His presence has always ruffled feathers. In 1932, concerned citizen Walter L. Long filed a complaint to the Home Office, appending a sketch of a naked man covered where appropriate with a paper flap. "If this sketch offends," Long wrote, "please remember that we have the same subject facing the main road from Dorchester to Sherborne."

He hinted that the virility symbol should be neutered. "If the Cerne Giant were to be converted into a simple nude, no exception would be taken to it. It is its impassioned obscenity that offends all who have the interest of the rising generation at heart, and I appeal to you to make this figure conform to our Christian standards of civilisation."

Apparently at a loss, a bureaucrat at the Home Office wrote in a minute: "This is a serious charge of indecency against a scheduled prehistoric national monument, made {hellip} after a lapse of 2,000 or 3,000 years. What does the complainant want us to do? Plant a small grove of fig trees in a strategic position?"

Because the giant was a national monument the Home Office chose to do nothing, but the fact that he survived intact is paradoxical. After all, one still can't show a real erection on British television.

The Cerne Abbas landmark, however, looks set to endure and amuse - and embarrass - indefinitely.Cerne Abbas, on the A352 a few kilometres north of Dorchester. For details, contact Sherborne Tourist Information Centre, (44) 1305 267992 or e-mail S.TIC@westdorset-dc.gov.uk.