Here's why a tiny city in South Sudan is the most expensive in the world for expatriates

Juba, South Sudan - population 300,000 - doesn't seem like it should be the most expensive city in the world for expatriates, but it is.

With an enduring civil war, brutal exchange rates, and a lack of infrastructure, the city is an increasingly expensive choice for foreign workers and their employers.

That's according to Steven Kilfedder, a cost of living manager with the consulting firm Employment Conditions Abroad International (ECA).

ECA releases an annual report on the most expensive cities in the world for expats. In its 2015 findings, Juba shot from ninth to first place.

Infrastructure in the region - both financial and physical - is in poor shape.

A landlocked country, many of South Sudan's main thoroughfares are dirt, and a recent civil war is making it even more difficult to move goods throughout the country.

The international-quality goods that do make it into the city are very expensive. Additionally, very little of what an expat would need while in Juba is actually produced in the area.

The latest exchange rates in South Sudan also weigh heavy on international workers. According to Kilfedder, the official South Sudanese pound is closely tied to the US dollar. Since the dollar has been doing so well, the value of the South Sudanese pound has gone up as well.

Meanwhile, 2014's second most expensive city for expats, Oslo, Norway, has fallen to number 11 this year. Kilfedder says it's due to a depreciation in the Norwegian krone