This is a fantastic, giant LEGO version of Arkham Asylum, created by Australian LEGO enthusiast Dayton.
His model of the well-known institute (via Brothers-Brick) for DC villains has a whopping 18,000 blocks inside and took around 4 months to build and collect all the necessary pieces.
I feel this was the milestone for me as a builder as this is something I have wanted to build for years now and I am so happy with how it turned out, almost everything I wanted to put into the moc was built and included, some of my favourite parts of the Moc are, Killer Croc's Cell (See Youtube Video) the Maximum Security Wing (Underground Cells), The whole interior turned out pretty good and I really like what happened the whole roof and clock part of the building.
Gotta love the underground cells! Here's a cool video showing all the build's features, all rooms and cells, and how LED lighting in it works: