Heogabawi is a natural rock cave below Tapsan in Gayang-dong, Seoul. A legend holds that Heo Seon-mun, the founding ancestor of the Yangcheon Heo clan, lived there and that Heo Jun compiled Donguibogam there. The cave is about 6 meters wide, 2 meters high, and 5 meters long, with room for more than ten adults. The inside cannot be seen from outside, so the cave feels less vivid.