Nauru

Located in the Micronesia subregion of the South Pacific Ocean, Nauru stands as the world's third-smallest country by area and the smallest republic, covering just 21 square kilometers. This microstate operates as a parliamentary republic with Yaren serving as its de facto capital and utilizes the Australian dollar as its official currency. Economically, the nation maintains a GDP per capita of approximately $10,125, driven by its status as a client state of Australia and its role in hosting an offshore immigration detention facility. Despite its limited landmass, Nauru supports a population of nearly 12,000 people, achieving a high population density that ranks it among the most densely populated nations globally.