LEGO builder Alice Finch spent a year building a replica of Hogwarts School of Witchcraft & Wizardry from J.K. Rowling’s Harry Potter book series out of 400,000 LEGO pieces.

It would’ve been impressive enough had she just built the exterior of the building, but Finch also painstakingly created each room of Hogwarts Castle in great detail.

The entire school grounds took 12 months to build, more than 40 boxes and pallets to get it to the convention center, and four people to set it up over three hours.