Korean currency
The yen was the currency of Korea during the Colonial rule, from 1910 to 1945, and was issued by the Bank of Joseon It was equivalent to the Japanese yen and consisted of Japanese currency and banknotes issued specifically for Korea. It was replaced by the South Korean won at par in 1945, and by the North Korean won in 1947.
Dandong
A substantial portion of North Korea's international trade, both legal and illegal, passes through Dandong and Sinuiju, across the Yalu River in North Korea. China handles roughly 40% of North Korea's worldwide export trade ($1.58 of 4 billion USD) and roughly half of the bilateral commerce with China goes through Dandong which imports $468 million [USD worth of product], according to its Ministry of Commerce. Dandong's annual resident per capita wage income for 2004 was somewhere between ¥9,500 and ¥12,237 RMB and the city's GDP was 3.77 billion USD.