Place rectangular bricks on the base plates to start your wall. Form the first layer of your castle wall by attaching rectangular LEGO bricks to your base plates. Place them end to end so they're touching and form a single layer. If you want to give your castle a classic look, use gray bricks.
How do you build a Lego castle tower?
https://www.youtube.com/watch?v=SNSSXXXndMM
How do you build a LEGO Round Tower?
https://www.youtube.com/watch?v=QW89IEKEF-Q
Is there a Minecraft Lego game?
LEGO® Minecraft™ brings one of the most popular video games ever into the real world. Physical bricks and pieces bring all the action, adventure and fun of the creative construction game to life.