Izayoi's mansion

Izayoi's Mansion is a location that was first introduced in InuYasha the Movie 3: Swords of an Honorable Ruler. It is the site of the Great Dog Demon's passing.

History
In winter of 1296, Izayoi was residing in the mansion whilst she was in labor with her unborn child at the birthing chamber during the night of the lunar eclipse. Takemaru acted as a guard. As the moon darkens, a first half-dog yōkai was born and even though the Great Dog Demon have entered the mansion, and Takemaru tells him a little late that he dispatch her that makes him mad. But Takemaru have ordered his men to set the mansion on fire "with the demon and everyone inside, burn it to the ground", as his men shoots the arrows with fires. As the Great Dog Demon enters the birthing chamber and hearing his second son crying and seeing his wife killed, he used the Tenseiga to resurrected her and gave her the Robe of the Fire-Rat from the fire until Takemaru arrives. He drew Sō'unga as he named his second son "Inuyasha" before he let Izayoi to get out as he produce the Dragon Twister until the mansion collapse. After the death of Tōga and Takemaru, the Tōga's vassals Myōga, and Tōtōsai, have arrived as well as Saya came out of the his seal of the sheath of Sō'unga for the meeting. Since Myōga placed the Tessaiga in his master's tomb in the Border of the Afterlife and hid the Black Pearl, and Tōtōsai did gave the Tenseiga to his friend Bokusenō that its for Sesshōmaru as leaves one problem: Sō'unga. They couldn't think to dispatch the sword, Saya thinks to let Sesshōmaru possess Sō'unga just like his father did, but Tōtōsai refused as he's already upset them as it is, over being bequeathed Tenseiga, if he find them, they'll all be killed, then Myōga said that they can't give it to Inuyasha because he's an infant. Saya suggests to hold Sō'unga quiet, at least for about 700 years. He tells them to throw him and the sword into the Bone-Eater's Well in the Musashi Province, he told them that he heard "if a demon's corpse is thrown into the well, it will simply vanish".

Hanyō no Yashahime
The palace made its main series debut in The Secret of the Rainbow Pearls where everyone across the lake witnessed the event of the building being burnt down and Riku saw it too that he realized it was too late to save him. 223 years later, Riku took Zero to the ruins as she realized that where Tōga's ashes were as the place where he the samurai Takemaru died, in preparation to force Towa's power to the surface. In The Three Princesses Strike Back, Myōga tells Moroha that those are the master's ashes which is her grandfather's, the place where he had perished, and Kirinmaru came to the same place. In Sesshōmaru's Daughter, Kirinmaru realized that Moroha as Beniyasha takes her demonic aura as her grandfather as he knew the place where he died.