The world's loneliest island is Tristan da Cunha.

Tristan da Cunha is a remote group of volcanic islands located in the South Atlantic Ocean. It is part of the British Overseas Territory of Saint Helena, Ascension, and Tristan da Cunha. The main island, also called Tristan da Cunha, is the most isolated inhabited island in the world.

1. Geographical Location:
- Tristan da Cunha is situated approximately 2,816 kilometers (1,750 miles) west of the southern coast of Africa.
- It is about 3,360 kilometers (2,088 miles) from South America.
- The nearest landmass, Saint Helena, is around 2,431 kilometers (1,509 miles) away.

2. Population:
- The island has a very small population, with only around 250 residents.
- The population is primarily descended from the original settlers, who arrived on the island in the early 19th century.

3. Accessibility:
- Due to its remote location, reaching Tristan da Cunha is extremely challenging.
- There are no airports on the island, and the only way to reach it is by a seven-day boat journey from Cape Town, South Africa.
- The irregular weather conditions and strong ocean currents make the journey even more difficult.

4. Limited Contact with the Outside World:
- Tristan da Cunha has limited contact with the outside world.
- The island has no internet access, and communication with the mainland is primarily through a radio telephone.
- The infrequent supply ships bring essential goods and provide a means of transportation.

5. Self-Sufficiency:
- The islanders rely heavily on fishing and subsistence farming for their livelihood.
- They have developed a strong sense of self-sufficiency and resilience to cope with the challenges of living in such isolation.

In conclusion, Tristan da Cunha is considered the world's loneliest island due to its remote location, small population, limited accessibility, and minimal contact with the outside world. Its isolation has shaped a unique way of life for the inhabitants, making it a fascinating place to study and understand the impact of geographical isolation on human settlements.