My countries with the most inland surface water is my most popular quiz so I thought I would try this -- countries who have no inland surface water. I took it from the same Wikipedia list but some countries listed such as East Timor, Georgia I double checked with Google Maps and took off the list. Other countries had seasonal rivers and were kept.
I'm impressed you've been there; not an easy place to access. I'm not sure why I didn't think twice about Bhutan - mountains with glaciers should have surface water.