(Newser) – Five months after it was shut down amid increasing tension between the two Koreas, the Kaesong Industrial Complex has re-opened. Hundreds of South Korean workers crossed the border today to resume operations at the factory park, one of the only symbols of cooperation between North and South Korea and their only remaining joint project, Reuters reports. North Korea pulled its 53,000 workers from the complex in April, but relations have recently thawed and the two nations have held talks. The BBC calls this a "trial restart."

The 820 South Koreans who enter today will assess the facilities to see how soon they can completely restart operations; more than 20 of the 123 South Korean companies that operate there are expected to be up and running today, the Wall Street Journal reports, and North Korean workers have also showed up. During weeks of negotiations, North and South Korea set up a joint management committee for the complex, and that committee has agreed to expand South Korean access to the site. The complex will also be opened to foreign investors, which could make it more difficult for North Korea to shutter it again in the future. (Another unusual development between the two countries happened on Saturday.)