Nathan and Manya's house is are two cobbled together bus sections to make a home for Nathan and Manya Vargas. Despite having lived in Megaton longer than anyone else, these modest home owners share one of the smallest spaces in town. This could be due to the larger ones being built and renovated later on as the town became more stable, popular, and better established.
The house is in the shape of a "T", made by two parts of a bus attached together. The inside of the house is more or less threadbare, with occasional miscellaneous junk like cigarette cartons and alcohol on the shelf inside.
Nathan and Manya's house appears only in Fallout 3.