The book consists of three sections of contributions representing novel ideas focusing on the quantity, quality, and actual condition of the monumental built environment of the ancient Maya in the northeast of the department of Peten, Guatemala. A special catalogue is its major contribution. It includes detailed, systematic and updated descriptions for comparative purposes. 64 archaeological sites are described in the form of technical data sheets, some of which are reported for the first time. In addition to the descriptions, the sites are illustrated by plans, isometric views, and several by photographs. In total, the two volumes of the catalogue (the first volume published in 2001: Ciudades Mayas del Noreste del Peten, Guatemala. Un estudio Urbanistico comparativo by Quintana and Wurster) include information on 128 sites, providing a concise and comparative summary through nine charts. These charts show the location of the archaeological sites in the landscape, the visible urban and architectural elements, the register of illegal excavations by looters, the register of visible architecture presently in danger of collapse, as well as the priorities of conservation. The systematic corpus of architecture permits the realization of an analysis of urban space. For this reason a methodology has been adapted, which was developed by two scientists of the Graz University of Technology, Austria, and basically involves the study of ancient urban space based on five different levels, with more than 64 variables. The results give evidence to the quality and large quantity of spatial solutions. Moreover, they show that the analysis of the constructive details or materials requires additional studies. The book also covers aspects of conservation, presentation and use of the built environment as part of the National Heritage. Here the particular concept is explained, designed and employed during twenty years of interventions in ancient Maya structures at Tikal, Yaxha, Nakum, and other sites. The applied proceedings are described in detail in four different sections. Consolidated and restored ancient Maya cities in areas ready to attract visitors are important landmarks for the future of the archaeological heritage of the north eastern Peten. The structural interventions in the new National Park Yaxha-Nakum-Naranjo, bordering the Tikal National Park, demonstrate these achievements, and represent an example of a successful and long-standing international cooperation between Guatemala and Germany, via the Deutsche Entwicklungsbank (KfW), the German Institute of Archaeology (DAI-KAAK), and the Guatemalan General Directorate of Cultural and Natural Heritage.