The COVID19 pandemic has put renewed focus on cities as hotspots for COVID19 outbreaks due to its connectivity with for example other cities, the high population density and mixing and reliance on public transport. Two of the most effective prevention measures hygiene (including wearing masks) and social distancing have a large effect on the behaviour of citizens, and require a rethink of the urban model and life. Is this the end of the city, or the beginning of the remodelling of the city? Half the world population lives in cities and this is likely to increase to 70% over the next 20 years. Cities provide jobs, are centres of innovation and wealth creation, but also often are hotspots of air pollution (e.g. particulate matter, NO2), noise, heat and disease. The high density of buildings and roads can cause so-called urban heat islands, defined as built up areas that are hotter than nearby rural areas. Furthermore, cities often lack accessible green space and physical activity levels of people are below recommended guidelines. They also generate a large proportion of CO2 emissions, and contribute significantly to the climate crisis. Recent estimates show that 60-80% of final energy use globally is consumed by urban areas and more than 70% of global greenhouse gas emissions are produced within urban areas. Up to 9 million people die each year because of ambient air pollution levels, 3.2 million because of lack of physical activity and 1.2 million because of traffic accidents. Noise causes more than 1.8 million DALYs a year in Europe alone and heat may cause as much as around 0.4% of premature mortality annually worldwide. A large part of the burden falls on cities as that is where people live and where higher exposure levels are. Population growth, ageing and the climate crisis put a further burden on cities in many aspects, including health.There is good evidence that there is a direct relationship between urban design, how people get around, and how this affects environmental exposure and life style factors and thereby morbidity and mortality. For example, in a city designed for and with large investment in infrastructure for cars, you will get many people using the car. On the other hand, in a city designed for and with investment in infrastructure for active transportation such as cycling, you will get more people cycling. As a result of the pandemic we see many European cities to a model that encourages cycling, partly because people avoid using the public transport system and there is not enough space for everyone to go by car. In this book I describe the issues and changes in the cities during the pandemic and that, as much as cities may be the problem, they could also be the solution through a transformation in their urban and transport planning practices. It is based on 10 short published posts on blogs between March and September 2020. The bottom line is that the pandemic can be catalyst for change and well planned and managed cities could provide an excellent and efficient habitat for the large human population and could not only be sustainable and liveable, but also healthy. I focus on important interventions, policies and actions that can improve public health, including the need for land use changes, reduce car dependency and move towards public and active transportation, greening of cities, visioning, citizen involvement, collaboration, leadership and investment and systemic approaches.