Kunta Kinteh Island, or James Island, is an island in the river Gambia that can be reached via the North Bank, so a trip on the ferry over the river Gambia is included. It is a world heritage location that is important historically because it used to be the place where slaves were collected before they where shipped to the Americas. The involves a drive across the North Bank of 2 hours along villages, and a boat from Albreda to the island and back. Guided tours on the island are not included in the price.
The excursion will take around 8-10 hours from start to return at your hotel. This depends on when the ferry goes.