North Korea has built an extensive barrier around the entirety of Pyongyang since the start of the pandemic, analysis of satellite imagery shows, in what experts say appears to be a massive effort to control the spread of disease and limit access to the country’s capital and largest city.

DPRK authorities first began to construct the barrier in Feb. 2020, and as of September, it has grown to feature 63 kilometers of fencing, at least 28 barracks for guards and an estimated 1,000 guard posts, according to the author’s analysis.

Google Earth satellite imagery reveals that the