The Three Shire Stone is a boundary stone that marks the location where the historic English counties of Lancashire, Cumberland and Westmorland meet.
Triple Frontier in South America
Four Corners Monument in the United States – pick your favorite three states and get a bonus for free
Tripoint of Thailand, Laos and Myanmar, located on a sandbar in the Mekong
Tripoint of The Congo, Tanzania and Zambia is in Lake Tanganyika
Beyond this gallery
Many more fine images can be found at List of tripoints.