High Quality Content by WIKIPEDIA articles! The Walasi-Yi Interpretive Center is a small brick building located along US 19/129 at Neels Gap, Georgia, on the eastern side of Blood Mountain. It is notable as the only place where the 2,175-mile-long Appalachian Trail passes through a man-made structure. It is currently the first mail-drop available to northbound thru-hikers that does not require one to leave the trail.