The Bay of the Broken Heart is a bay that is supposedly haunted by the spirit of Chinhilda, the wife of Grimbeard the Ghastly and mother of Hiccup Horrendous Haddock II.
History
When Hiccup II was deemed a runt by the Naming Dame, Grimbeard stole him from Chinhilda and as result she attacked him, but was defeated and banished. During her banishment Chinhilda spent the rest of her life searching for Hiccup II, thus she became the spirit that haunts the Bay of the Broken Heart and supposedly shouts "Hiccup! Hiccup!", desperately searching for her son.
Appearances
How to Break a Dragon's Heart
The Hooligans go camping on the bay during their search for Camicazi. They are ambushed by Ug the Uglithug and his men. Ug makes a proposal to Stoick about the love letters being sent to his daughter. While trapped inside a tree prison on Berserk, Excellinor tells Hiccup III the story of his ancestors 100 years prior including the Bay of the Broken Heart. In the epilogue an elderly Hiccup says he has dreams about being being Chinhilda.