The National Historical Museum commissioned a study that focused on the potencies of the access mechanism of a museum in an urban context. This was intended to result in a prototype design. The museum has neither a collection nor location and is intended to function first and foremost as a place for exchange and communication at the centre of its social context. The heart of the building consists of a large covered square that opens onto the public space of the urban fabric. From here a virtually inexhaustible matrix of increasingly intricate rooms is accessible. The museum as a complex of rooms, navigable via endless enfilades. The rigid structure enables both a chronological and a stage-managed layout. The spaces between the rooms accommodate all the circulation zones and support functions. This makes it is a matter of a formal circuit of routes and facilities. At the same time, the structure of the rooms also allows for endless rambling. In this permeable structure intended to enable a dynamic institution to flourish, the boundary between public space and museological exhibition becomes blurred.