The Long Coast's Vista Point tower is found at the mouth of a river South of The Greenhouse where the "Seeds of the Past" Main Quest takes
Horizon Forbidden West - Vista Point: The Long Coast Walkthrough
Horizon Forbidden West Gameplay Walkthrough - Vista Point: Long
Where to find every Vista Point in Horizon Forbidden West - Polygon
Vista Point: The Long Coast - Horizon Forbidden West Guide - IGN
Relic Ruin: The Long Coast - Horizon Forbidden West Guide - IGN
Relic Ruin: The Long Coast - Horizon Forbidden West Guide - IGN
Vista Point: The Long Coast - Horizon Forbidden West Guide - IGN
Horizon Forbidden West Gameplay Walkthrough - Vista Point
Vista Point: The Long Coast - Horizon Forbidden West Guide - IGN
The Long Coast Vista Point Horizon Forbidden West (Find Where
How to find Vista Point: The Long Coast in Horizon Forbidden West