The Cultural Heritage plays an important role in defining the identity of Europe as compared to the rest of the World, influencing the feeling of attractiveness for its citizens as a place of work, living and visiting. It increases also the feeling of togetherness among European citizens. Therefore, the need for protecting and preserving European Cultural Heritage is of extreme importance for combined European cultural wealth. The European cultural heritage is enormous, with a vast and rich variety of cultural items, ranging from buildings to museum artefacts. These items consist of materials of diverse types, the condition of which deteriorates with time, mainly due to environmental conditions and human actions. This strengthens the need for the effective documentation of the cultural items, so that information about them is easily accessible to researchers and the public. The preservation of objects against the effects of time to be passed unaltered to next generations, are also matters of uttermost importance and have attracted significant focus. Factors responsible for the deterioration of the state of cultural items, in case of indoor environments, include but are not limited to, humidity, temperature, exposure to light, as well as the effects of human activities, such as the transportation of the items. These factors are eliminated by keeping the cultural items in specifically designed facilities, such as museums and galleries, where environmental conditions are controlled by following specifications established after extensive research. However, there is a lack of research concerning the effect of the environment and the means to eliminate it, in cases of uncontrolled indoor environments. Such cases include objects and artworks hosted in historical buildings and monuments of public access, where people activities are not restricted, as in museums. The increased human activity, in combination with the uncontrolled environmental conditions of such facilities affects the objects of interest in a significantly higher degree, than the controlled environment of a museum. In this respect, several monitoring and simulation technologies can be effectively used in order to assist in the documentation of cultural objects, as well as the evaluation of the effects of the environment on them and the development of procedures to handle those effects, to achieve preventive conservation. This article presents an ongoing work in the research project s ARCH, funded by the European Commission under Horizon 2020 program. It concerns means of better preservation of areas of cultural heritage from hazards and risks resulting from Climate Change. It develops tools that will help modern cities to preserve and protect their cultural heritage and historical areas from multiple negative effects of Climate Change. Tools and methodologies are designed for local authorities and practitioners, urban population, as well as national and international expert communities, aiding authorities in knowledge-aware decision making. We will focus attention in our presentation on a variety of sensors and sensing technologies for offering necessary data and beneficial information for being able to produce knowledge-aware decision support tools. Presented approaches range from satellite observations from Copernicus and respective climate and atmospheric monitoring services, through high/low altitude aerial observations to in-situ and mobile sensing at (near) ground levels using novel sensing technologies, some of which have been developed in collaboration with industry leaders such as Analog Devices (Ireland) or Turta (Turkey). Subsequently, application of acquired sensor data in a variety of tools built by other project partners shall be also presented.