I believe most of the cash was in dollars, though some was local currency. The cash was for missionary support funds and to pay several months' rent on missionary apartments and the villa where church services were held. In retrospect, what a stupid system - send 20-year missionaries...across an international border...with $15K cash!
We split up the cash amongst our wallets, various bags, and in between pages in our scriptures.
At the border, they changed the wheels on the trains to fit the new country's rail lines. So, we're sitting there in the train at the border at like 1am, when armed guards board the train and customs agents interview us. We declared a fraction of the cash. Had they discovered how much money we had on us, we probably would have been robbed, beaten, and left for dead in the snow at the remote border crossing.