Over the last decade, German housing prices have increased unprecedentedly. Drawing on quality-adjusted housing price data at the district level, we show that regional fundamentals explain up to two-thirds of between-region and 77 to 87 percent of within-region variation in price growth. Price increases were driven mainly by co-movements in local demand fundamentals, notably population density and skill level. However, we further reveal systematic variation unrelated to fundamentals: overvaluation of top 7 cities, path dependency, and spatial spillovers. We infer that speculation, investor preference for liquid markets, and bounded rationality contributed substantially to the recent housing price boom in Germany.