The LEGO DUPLO theme was introduced as far back as 1969 and is designed for children ages 1 to 5. It features DUPLO figures which are much larger than minifigures and DUPLO blocks which are about twice the length, width, and height of a standard System brick. Like LEGO System, DUPLO also has subthemes that are often junior versions of System themes, like Pirates and Castle and licensed themes like Disney and Super Heros.
2006 LEGO Sets
2006 for LEGO was a year of new themes being introduced and a number of well known themes being retired. LEGO in 2006 introduced and discontinued The Avatar: The Last Airbender, introduced the original Batman theme, Exo-Force, Mindstorms NXT, SpongeBob SquarePants, Remote control Trains and Aqua Raiders. However, the following themes were discontinued; Clikits, Vikings. While LEGO Sports was re-introduced in 2006 with a couple Soccer/Football sets.