The main island of Japan, Honshu, is the most densely populated of Japan's four major islands. The next most densely populated island is Kyushu, followed by Shikoku and Hokkaido.
france and germany
New Jersey
The specifically of the question leaves much to be desired. Some places are densely populated for survival of the habitats of the people living in the area. Without technology, people and well most animals are restricted to places where water is easily accessible to live. In modern places, the densely populated places are cities that offer employment and often higher paying jobs.
Southeast England (centred around London) is the most densely populated part of the UK.
The most densely populated area in Russia is the city of Moscow and most densely populated area in Europe is the city of Paris.
The most densely populated island is Europe is Île Saint-Louis, a French island in the Seine River in Paris. Its population density is 22,409/km2.
Island of Java
Europe
The Netherlands
Monaco is the most densely populated country not only in Europe, but the entire world.
The island of Java is the most populated and the most densely populated island of Indonesia. The most dense province in Java is the Jakarta special capital region (DKI Jakarta), the capital city & province of Indonesia.
java
Barbados island.
Western Europe is very densely populated. In fact, it is one of the most densely populated places in the world.
penise
Monaco is the most densely populated country in Western Europe, all of Europe, and the world.