North Korea appears to be expanding a coastal air defense missile base located 50 miles from the South Korean border, according to NK Pro analysis of satellite imagery.

The large-scale military project began in July around Lake Tongjong, a beach lagoon in Thongchon County on the southeastern coast.

Planet Labs imagery shows efforts to build new infrastructure next to missile launch installations, as well as new roads from a nearby highway into the base and around the lagoon. 

A channel is also being dredged to open the lagoon to the ocean and a new dock has been built at the north end of the beach, suggesting the project may involve a naval component.

Experts told NK Pro the base appears to host SA-5 surface-to-air missiles (SAMs), a long-range missile developed over 60 years ago by the Soviet Union. 

High-resolution Google Earth satellite imagery shows that launch positions were first established from 2017 to 2018 while missiles appeared on launchers by 2022. The base also features support infrastructure like radars, garages and large trailers for transporting missiles and launchers.

Authorities appear to be in the process of razing an entire village of over a hundred houses just north of the base to facilitate the latest base expansion, and more houses have been torn down in the larger town to the south to make way for the new roads.

But many homes in the area, as well as hotels and new facilities at the Jasan Bathing Beach, remained intact as of late last month, according to Planet Labs imagery taken on Aug. 27. 

Construction of around 20 apartment buildings nearby to the west has proceeded rapidly since early July, likely for residents displaced by the demolitions. 

More apartment buildings have been built at the same time on the primarymain road in the main town of Thongchon down the coast as well, in addition to new factories, a hospital and other facilities under North Korea’s “20×10” rural development project.

North Korea weapons expert Joost Oliemans told NK Pro the Soviet-designed SA-5 (also known as S-200) is a long range weapon that can “swat strategic aircraft from the sky from a very long distance.” (See here for more details via NK Pro’s new Weapon Directory tool, based on a book series co-authored by Oliemans). 

But the SA-5s at the Thongchon base are “exposed” and even with such protections they have “next to no survivability during conflict,” he said, citing successful recent U.S. attacks on Iranian SA-5 installations. He previously described it as a “thoroughly outdated” system when the DPRK displayed the missiles at a military parade in 2017. 

North Korea notably fired an SA-5 into the water just off South Korea’s east coast in 2022.

It’s also possible that the latest construction project will result in switching out the SA-5s for newer weapons systems.

North Korea has been developing and testing the Pyoljji series of short– and long-range SAMs in recent years, often from mobile tube-launched systems on detachable trailers.

One test was from a new destroyer as well, a sign Pyongyang seeks to use warships to demonstrate its previous threats to shoot down U.S. and South Korean reconnaissance aircraft operating in international airspace off the DPRK’s coasts.

New warships and submarines are slated to be stationed at North Korea’s first modern naval base now under construction up the coast in Munchon. NK Pro reported last month on the resumption of this project after years of delays, and the latest satellite imagery shows that large-scale construction has started and thousands of workers have arrived on site. 

DPRK leader Kim Jong Un announced a plan to “renew all military bases toward standardization” over the next five years at the Ninth Party Congress in February.

Edited by David Choi