The “Two roads taken” project aims to implement the best of the two schools of thought regarding the marking of nuclear waste facilities. The first approach calls to seal the site completely and erase any sign of human intervention at the site, as if no activity ever took place, and hope no one will come across it by mistake. The second approach calls to give clear signs for the content and the danger that lies underground. In order to use two such different approaches, two very distinct structures are designed.
The SIGNIFIER is an above-ground structure, designed to be seen from afar and to convey a sense of danger. It is a spiral walkway and an observation point. Along the walkway is a display of warning and information in multiple forms (as explained). The SIGNIFIER must be maintained regularly, if not, it will decompose and vanish from the face of the earth, leaving the site as if a human hand has never touched it. 
The second structure, The UNDERWORLD, is a concealed, excavated structure built directly on top of WIPP’s waste shaft. It is built to last against wear and deterioration for ages. Once completed, The UNDERWORLD will be sealed. It will provide information and warnings in a variety of forms to its discoverers, and will still preserve the option to access WIPP.