Chernobyl’s New Safe Confinement Dome is now in place over the radioactive remains of Reactor No. 4. It is the world’s largest movable land-based structure.

The 275 m by 108 m shield was gradually inched over the grounds using a system of hydraulic pumps

The giant shell was built away from the reactor because radiation levels above it are still extremely high. Construction took about 10 years.

Back in November, Product Design & Development offered this update, detailing the progress. The installation was completed Wednesday.