Princess Grace's son visits Newgrange

Prince Albert of Monaco and his wife, Princess Charlene paid a private visit to Bru na Boinne and Newgrange on Wednesday.

The couple, who were with a group of friends,  paid a very informal visit, according to chief guide, Claire Tuffy.

'We did get avance warning, but we didn't have to close the site or restrict visitors.

'There was no standing on ceremony. It was very informal and very pleasant.'

The couple arrived at the visitors centre at around 1pm on Wednesday and their party was given a tour of Newgrange by guide, Sharon Downey, one of the long term guides a t the centre.

'We were delighted to have them. They were on a short holiday to Ireland and Newgrane was on their to do list. They were very relaxed and there were a lot of other visitors about, but the majority had no idea who they were.

It is believed the couple visited the Monasterboice Inn for lunch afterwards.

Newgrange has always attracted VIP visitors, the last being American vice president Joe Biden who paid a visit to the national monument as part of an official visit to Ireland last June.

Many Royals have also made their way tot he Royal County. Those who have visited the megalithic burial chamber include Prince Charles of England, The Duke and Duchess of Luxemburg, The Queen of Norway, King Juan Carlos of Spain and Japanese Emperor Akihito, when he was crown prince.

Prince Albert Alexandre Louis Pierre Grimaldi (58) is the reigning monarch of the Principality of Monaco, and head of the  House of Grimaldi. He is the son of Rainier III, Prince of Monaco, and American actress Grace Kelly. Prince Albert's sisters are Caroline, Princess of Hanover, and Princess Stéphanie. In July 2011, Prince Albert married South African, Charlene Wittstock.

Prince Albert II is one of the wealthiest royals in the world, with assets valued at more than $1 billion, which includes land in Monaco and France.