The mudflood theory presents the idea that a worldwide cataclysmic event, often described as a sudden inundation of mud, occurred in the relatively recent past—perhaps in the 18th or 19th century—burying cities, monuments, and entire civilizations under several feet of sediment. Proponents of this perspective point to countless buildings across continents that appear to have lower floors, windows, or doors buried beneath present-day street levels. These architectural anomalies are not limited to