According to conventional wisdom, property has disintegrated. Property law has undergone many changes since the heyday of Legal Realism, and many of these changes were both inspired by Realism and went under the banner of the Realists’ “bundle‐of‐rights” conception of property. However, many of the features of property law most denigrated by the Legal Realists and their successors have proved surprisingly resilient. These “doctrinal” features include the notion of property as a thing, the importance of possessory rights, and the greater degree of formalism in property than in contract law. In this Article, I argue that there is a common cause to the Realists’ criticism of these features and their endurance in the face of that criticism: all of these features of property are manifestations of property law’s basic architecture as a system. Because of the inherent complexity of relations—especially those that are less personalized—in private law, a system for providing a first cut at managing these relations presents problems of information costs that are unique to property. These costs, usually left out of realist analysis, are hard to ignore entirely and push property law to treat private interactions in a more modular fashion than the realist bundle‐of‐rights picture would lead one to expect. Moreover, the underappreciated flexibility and robustness of a modular architecture allows property law to absorb—at some cost—a great deal of change without alteration of its basic nature. I apply this analysis to Realist and post‐Realist approaches to asset definition, trespass and nuisance, and the standardization of property forms. The greatest engine for change from Legal Realism in certain areas of property may be simple ignorance of the complexities of earlier law.