Architecture is differentiated from building in that it is deemed to induce sensations of delight or wonder in its observers. The paper takes the metaphor of a trivial machine and argues that a work of architecture is the physical embodiment this. The process of constructing such a machine for the first time is not trivial and can induce sensations of delight in an observer. This applies both to the observer who designs the machine (the architect) and to the observer who passes by and who reconstructs it in his or her understanding. Can trivial machines be constructed which have some of the attributes of non-trivial machines in that the output is continually surprising and new? When a trivial machine is nested inside another machine whose function is not fully known the result is an inverted, non-trivial machine in Von Foerster’s terms. The paper argues that physical architecture can be observed in this way.