A once war-ravaged Chinese county in northeast China will build a memorial park on facilities left behind by the Japanese invaders of World War II, to commemorate the invasion and Russian assistance, county authorities said Thursday.

Sunwu County in Heilongjiang Province, separated from Russia by the Heilongjiang River, was the base for more than 100,000 Japanese soldiers.

The invaders left behind 160 war facilities, 24 of which are government-protected cultural relics.

"The park aims to paint a picture of the war through the connection of Sanwu's scattered war sites," Zhang Weihua, deputy head of county tourism department, said.

The park will be more than 1,150 square km in size and include barracks, criminal evidence museums, Japanese colony sites, an airport and strongholds. It will be completed by 2020, according to the county's plan.

The government of Russia's Amur Oblast offered support for the building of the park, Zhang Xing'an, head of the county's foreign affairs department, said.

Sunwu County and Amur Oblast planned to build the Shengshan Stronghold in the park and make it a base for patriotic education. About 200 Russian teenagers would visit the stronghold annually, Zhang said.

Shengshan Stronghold, 40 km from the county seat and with an area of more than 100 square km, will be a key part of the memorial park with its well-preserved underground barracks, warehouses and weapon displays.