It's quite an unusual experience stumbling into a pyramid in the middle of an Irish forest! This pyramid was built in the 19th century as a burial chamber for Lord Garvagh and is a lovelly feature to the forest today.
If you walk 100m slightly off the path south at this waypoint, you'll reach the beautiful little Altkeeran Waterfall. The waterfall is situated nearby to the spring Source Of The Grillagh and the peak Carntogher.