Is there any part of the world that has not been explored?

There is no part of the world that has not been discovered or been explored. However, there are still some places that are poorly understood or have not been fully explored due to their remoteness, harsh environment, or political restrictions. Some examples include:

- The deep ocean: While the surface of the ocean has been extensively mapped, the deep sea remains largely unexplored due to its extreme pressure and darkness. Only a small fraction of the ocean floor has been explored in detail.

- Remote mountain ranges: There are still some mountain ranges that are poorly understood due to their inaccessibility and challenging terrain. For example, the Hindu Kush and Pamir mountains in Central Asia and the remote highlands of Papua New Guinea are still relatively unexplored.

- Polar regions: The Arctic and Antarctic regions are challenging to explore due to their extreme weather conditions and harsh environment. While significant scientific research has been conducted in these regions, there are still areas that remain largely unexplored.

- Dense tropical rainforests: Some dense tropical rainforests, particularly in remote parts of the Amazon rainforest, the Congo rainforest, and the rainforests of Southeast Asia, are still relatively unexplored due to their dense vegetation and difficult terrain.

- Protected or restricted areas: Certain areas of the world may be protected or restricted due to political sensitivities or cultural significance, making it challenging to explore them freely. Examples include North Korea, certain parts of the Arctic and Antarctica, and sensitive military installations.

It's worth noting that even in places that have been explored, there is still potential for new discoveries and scientific research, as advancements in technology and research techniques can often reveal new information and insights about previously explored regions.