Urban growth is typically considered a process of expansion. As population grows and transport costs decrease urban density gradients are expected to gradually flatten. This is a basic feature of cities, explained by urban economic models and empirically supported by a plethora of studies about urban density development from all over the world. However, additional forces, such as changes in demographic composition and locational preferences of the urban population acting at local levels, may counteract the flattening tendency of urban gradients. In this paper, we suggest a methodology to test the impact of local density changes on urban gradients, looking at spatio-temporal developments in terms of housing and population. Using highly detailed data on individual housing units and inhabitants in major Dutch cities, we first assess and compare urban density gradients during the period 2000?2017. In all the analysed Dutch cities, both dwelling and population density gradients are becoming steeper over time, contradicting standard predictions from urban economic literature and empirical reports worldwide. The observed trend of steepening urban gradients is partly explained by the presence of historical monuments and urban amenities.