In Hong Kong, space has always been at a premium. The small autonomous territory, part of the People's Republic of China, houses more than 7.3 million residents within just 426 square miles (1,104 sq kilometers)—resulting in one of the highest population densities in the world: 17,150 people per square mile (6,650 people per sq kilometers). In such a limited and popular environment, developers tend to build as tall as possible, leading to a bristling cityscape that has led some to call Hong Kong a concrete forest. Reuters reports that home prices in Hong Kong have risen by 120 percent since 2008, with prices in the luxury market being pushed up by wealthy buyers from mainland China. The market has cooled in recent months as investors wait to see which direction China's slowing economy will trend.