Bhutan has 20 administrative districts, which are entitled as Dzongkhag. Some highly populated Dzongkhag contains sub-district, which is named Dungkhag. There are total 13 Dungkhag in Bhutan. Each Dzongkhag are separated into a few “Gewog". You can imagine the size of each “Gewog" is just the collection of a few small villages.
“Dzong” is the main building for each Dzongkhag. “Dzong” looks like a traditional Bhutan-style castle, which may easily misunderstood as the palace of the royal family. However, they are actually the government office, where those important policies are made here. Moreover, there are indoor-temple for the monk to worship. “Dzong” can be regarded as the most representative building in Bhutan.
In the old time, Dzong’s main function is to defense the enemy. Therefore, they are always built next to the mountains or rivers. No nails were consumed when the Bhutanese built the Dzongs. You can never imagine such a great building was built without one single nail.