Architectures “on ruins” and ambiguous transparency: the glass in preservation and communication of archaeology

The contemporary architecture is characterized by an even more marked "transparency", as a result of a continuous experimentation all directed towards the research of the built "lightness", that is towards the "dematerialization" of the architecture and the consequent loss of weight connected to the excess of form. It’s in 1851 that a New Architectural Age springs because of the realization of the Crystal Palace, in London – that has addressed towards the experimentation of the glass as an architectural, structural element and of design. Today, part of this experimentation has been applied for some interventions of coverage, protection and communication in situ of the archaeological ruins. Also they are expressions that give consistence to an architecture of glass defined by a strong identity and a proper language. In these cases the "box of glass" plays a determining role in the definition of the atmosphere that edges the ruins. It happens however that the demands of protection – especially if treated without attentively reflecting on the meaning of the archaeological emergencies – the demands of guardianship conduct to the building of pure "containers", whose prominent characteristic seems to be the negation of the inside space, reduced to a simple transparent box. Some international representative cases of study will be exposed in which "transparency" has been used with a language and a more appropriate symbolism to evoke archaeological preexistences