A tiny red diary and an ID card figure in our Geo Quiz.
The red diary in question is a battlefield diary kept by a fallen North Vietnamese soldier. A US Marine came across it in 1966 and kept it ever he returned home from the war in Vietnam.
It took awhile but that personal diary has now been returned to the Vietnamese soldier's family in a small village outside Vietnam's capital.
You can hear our interview with a history detective about how that reunion came to be but first: name the city that became Vietnam's capital in 1976.
This 1,000 year old city is located on the banks of the Red River.
Can you name it?
The soldier's diary that's at the heart of an upcoming episode of the PBS television series History Detectives was a personal battlefield diary of fallen North Vietnamese soldier Vu Dinh Doan.
His family lives in Cay village outside Hanoi, Vietnam's capital. Now 46 years after he died in action, Vu Dinh Doan's battle diary has been returned. Wes Cowan, the lead investigator for History Detectives who helped make possible the return of the soldier's diary, says the simple act of returning this battle diary marks an important diplomatic achievement.