The Lego brick, one of the world's most popular toys, was invented in the small Danish town of Billund in 1958. Created by Godtfred Kirk Christiansen, the plastic bricks can be combined in countless combinations and have sold in the billions. Kjeld Kirk Kristiansen, the inventor's son, was ten at the time. He used to play in the company workshop and helped test early Lego models. Olga Smirnova spoke to Kjeld Kirk Kristiansen for Witness History.

PHOTO: A boy playing in a Lego display in 1981 (Getty Images)