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.
2011 LEGO Sets
For collectors, 2011 was a significant year in that LEGO released the first Internal sets Moulding Machines (4000001) and LOM 2011 Moulding (4000002) which have paved the way for high value future collections. A few notable themes introduced in 2011 were Ninjago, Winnie the Pooh, SpongeBob SquarePants, Alien Conquest and LEGO Master Builder Academy. Of course LEGO Ninjago set the stages for a decade of collecting. However, in 2011 LEGO also discontinued a number of themes which included Ben 10, Power Miners, Toy Story, Prince of Persia, Space Police III, BrickMaster and the loved Trains theme.