In the aftermath of the world's worst nuclear disaster in Chernobyl in 1986, which resulted in radiation that ultimately reached as far as Japan and the US, the Soviet Union slapped together a massive sarcophagus of metal and concrete as hastily as possible to contain further fallout at the site of reactor 4.
With no welded or bolted joints and a leaky roof that led to corrosion "hastening its demise," it was never seen as a permanent solution, reports Live Science.
Construction began on its enormous replacement, the New Safe Confinement, in 2012. Now French consortium Novarka is using 224 hydraulic jacks to slowly slide the steel structure 1,070 feet to cover the ruins in Ukraine.
(The site is too dangerous to build over.) "The start of the sliding of the Arch over reactor 4 ... is the beginning of the end of a 30-year-long fight with the consequences of the 1986 accident," says Ukraine's minister of ecology and natural resources, per the BBC.
At 354 feet high, 531 feet wide, and 843 feet long, the $1.6 billion arch is taller than the Statue of Liberty and the largest man-made structure to ever move across land.
It should last 100 years and withstand a tornado. Next, robotic cranes will take the sarcophagus apart and vacuum cleaners operated by remote workers will remove radioactive dust.
This article originally appeared on Newser: Robots and Giant Sliding Dome Are Finally Sealing Chernobyl