The secrets behind Angelina's baby tattoos

After attending the world premiere of her latest movie, Angelina Jolie revealed her latest set of body art - geographical map coordinates accurately detailing the countries of birth of each member of her "rainbow family".

Walking down the red carpet in Cannes to promote her movie, A Mighty Heart, the 31-year-old actress kept the new tattoos hidden, using her boyfriend, Brad Pitt, as a human shield.

The tattoo on Angelina Jolie's left arm show's the map coordinates for the birthplaces of her children. The actress also appeared to be bruised - a common side effect of tattooing.

But as the couple made their way down the festival's famous Croisette in a chauffeur-driven car afterwards, the four-part scribing on her left shoulder was plainly visible.

Each line, it has emerged, represents the very international map coordinates detailing where their four children, three of which were adopted, were born.

From the top down, and from left to right, is the longitudinal and latitudinal location of Cambodia, where the Oscar-winning actress' eldest son, Maddox, five, was born.

Next are the coordinates pertaining to Ethiopia, the country from which Miss Jolie plucked two-year-old Zahara.