North Sentinel Island is one of the Andaman Islands, an archipelago in the Bay of Bengal which also includes South Sentinel Island. It is home to the Sentinelese, an indigenous people in voluntary isolation who have defended, often by force, their protected isolation from the outside world.

The Andaman and Nicobar Islands Protection of Aboriginal Tribes Act of 1956 prohibits travel to the island and any approach closer than five nautical miles (9.26 km) in order to prevent the resident tribespeople from contracting diseases to which they have no immunity. The area is patrolled by the Indian Navy.

North Sentinel is surrounded by coral reefs, and lacks natural harbours. The entire island, other than the shore, is forested. There is a narrow, white-sand beach encircling the island, behind which the ground rises 20 metres, and then gradually to between 46 and 122 metres near the centre. Reefs extend around the island to between 0.93 and 1.5 km from the shore. A forested islet, Constance Island, also "Constance Islet", is located about 600 metres off the southeast coastline, at the edge of the reef.

The Sentinelese have repeatedly attacked approaching vessels. This resulted in the deaths of two fishermen in 2006 and a US missionary, John Allen Chau, in 2018.

According to wikipedia.org