Ayoghara Jātaka (No.510)
The Bodhisatta was once born as the son of the king of Bārāṇasī. Both the earlier children of the Queen Consort had been eaten up by a she-goblin. For the third child, therefore, an iron house (Ayoghara) was built, and in this the Bodhisatta was born, hence his name, Ayoghara.
Meanwhile the she-goblin had died, but yet the Bodhisatta grew up in the iron house. When he was sixteen his father, wishing to give him the kingdom, had him taken in ceremonial procession round the city. Wondering at all that he saw, he asked why he had been denied the sight of all these things before. When told the reason, he reflected that all life was a prison, that though he had escaped the goblin, there still remained old age and death. Accordingly, at the end of the procession, he announced his intention of renouncing the world. His parents and many others being converted to his views, they followed him into the forest, where a special hermitage was built for them by Vissakamma under Sakka’s orders. J.iv.490‑99.