When New Zealander Daniel Gray and his girlfriend Kathleen Starrie decided to visit her family in Edmonton, Canada, for five weeks, Starrie’s mother Brigid Burton thought it best to come up with a hefty project to keep Gray occupied (and test his resolve): she tasked him with making a rainbow igloo in the backyard. Burton had collected a slew of milk cartons and used them, water, and food coloring to make colored ice blocks. Gray put his engineering prowess to work, drew up some plans, and started building, using “snowcrete” (snow mixed with water) to bind the bricks. Five weeks, 500 ice blocks, and about 150 hours of work later, the rainbow igloo was complete. For more, watch the story video and check out their full image set.

[via Colossal]