South Africa unveiled its latest monument to Nelson Mandela Saturday, a new statue along a rural highway marking the spot where he was arrested 50 years ago for his struggle against apartheid.

Mandela, now 94, was arrested as a young liberation fighter on 5 August 1962, near the eastern town of Howick, just months after he founded the armed wing of the African National Congress (ANC).

He had returned just a few weeks earlier from a trip across Africa drumming up support for the new Umkhonto we Sizwe (MK), or "Spear of the Nation."

The sculpture now on the site of his arrest is made up of 50 steel rods of between five and 10 metres (about 16 to 33 feet) high and when viewed from a certain angle, Mandela's image comes into focus.

"The front of the sculpture is a portrait of Mandela; it has vertical bars which represent his imprisonment," said the monument's designer, Marco Cianfanelli.

"When you walk through the structure it radiates like a burst of light, which symbolises the political uprising of many people, and solidarity."

South African President Jacob Zuma, Mandela's grandson Mandla Mandela, and others planted trees along a pathway leading to the monument in honour of the the Nobel Peace Prize winner.

At the foot of the trees, wooden signposts were inscribed with the words negotiator, courageous, statesman, leader, prisoner, comrade and character.

"We must encourage generations to visit the site because those who do will be inspired," said Zuma, who unveiled the monument.

Mandela's life dodging apartheid police while making appearances across the country earned him the nickname "Black Pimpernel."

He was arrested while travelling illegally to Johannesburg from Durban, where he had briefed ANC leader Albert Luthuli on his trip.

Police found him disguised as a driver under the false name of David Motsamayi, in the car of theatre director Cecil Williams.

His arrest about 100 kilometres (60 miles) from Durban led to 27 years of incarceration, until his release on 11 February 1990, an event that was watched around the world.

Mandela became South Africa's first black president in 1994, a unifying force after decades of white minority rule.

"I realised that to try and get away would be a gamble," Mandela said during a visit to the site of his arrrest in 1993, the year he won the Nobel Peace Prize. "I decided the game was up."

"The arrest itself was done very courteously, very politely. The policeman was doing his duty, he did it according to the law, he was courteous."

It was never known who tipped off the police.

"He did not make himself known to his friends, including me, because we were watched and followed. It came as a surprise to hear that he had been arrested in Howick," George Bizos, a lawyer and close friend of Mandela, told AFP.

"We learnt later that he was insufficiently cautious."

Mandela made a splash at his trial, arriving to defend himself in court sporting the traditional Xhosa garb made of leopard skin.

He was jailed for five years for organising an illegal conference abroad and for leaving the country without permission, before being sentenced to life imprisonment in 1964, when the authorities discovered he was the head of the ANC military wing.

The anniversary of the arrest "reminds the country of how far we have travelled", said Verne Harris of the Nelson Mandela Centre for Memory.

"Madiba now lives in a democratic South Africa, while 50 years ago he had to fight for freedom," he said, using the Mandela clan name, a term of respect.

"While we still have many challenges and reality is still harsh for many South Africans, we have come a long way."

The anniversary will also be marked by a new "Mandela Day Marathon" on 26 August that will end at the new monument.