The Jewelry House is a place that Hamtaro and his friends helped build after they met Lapis and Lazuli. It mainly serves purpose to the Ham-Hams by being the gate to Sweet Paradise. Apart from that, it is Lapis and Lazuli's house.
Not much of the indoors is shown, but it splits off into staircases on either side which lead to a second floor lined with several doors that lead to other rooms. One room is shown in Lady Lapis! as the main room where they have the usual bedroom furniture (wardrobe, mirror, etc) and a sofa (a basket). It also contains Lapis and Lazuli's beds; Lapis has blue sheets whereas Lazuli's are orange. In the same episode there is a brief showing of a very basic kitchen on the bottom floor. It is a long groove in the wall and is formatted somewhat like a bar. It seems to only contain a fridge and a counter. The bottom floor also has round tables with chairs dotted around. In the center of Jewelry House is a large bush/tree with a very large door at the base. The door is the portal to Sweet Paradise.