Arthur's House (アーサーの家 Āsā no Ie) is where the great hero Arthur used to live. He was killed before the game's events by The Doctor. Sue spends a lot of her time locked up here. For Quote, Arthur's house acts more as the main hub, being the place where you can teleport to the Egg Corridor, Bushlands, the Sand Zone, the Labyrinth (if Professor Booster was ignored there), and the Plantation, once unlocked, with ease. A lot of the game's plot also unfolds here.
- Red Flowers can be found in the lower level of the house.
- In Cave Story+ and the WiiWare port, the photograph on the wall has a picture of a rocket ship from one of Pixel's earlier games, Guxt. The whiteboard also has a small drawing of Ikachan from another of Pixel's games, Ikachan.
- There are 2 variants of Arthur's house in the coding of Cave Story, with different programmed events. The copy internally named "Pens2" is only for a single cutscene, that of Sue and Kazuma sending IMs to each other.
|General||Mimiga Village • Mimiga • Balrog • Bubbline • Cemetery • Ma Pignon|
|Characters||King • Toroko • Mahin • Jack • Kanpachi • Sandaime • Misery • Little Man|
|Enemies||Egg Fish • Pignon • Gravekeeper|
|Items||Map System • Silver Locket • Arthur's Key • Beast Fang • Mushroom Badge • Booster v2.0|
|Interactive objects||Teleporter • Fireplace|