The annual gathering of the African Borderlands Research Network (ABORNE) was held from 16-17 September in Lomé, Togo. Some 40 cross-border practitioners and experts analysed dynamics of border cities to shed more light on how the border setting shapes urban forms, livelihoods and aesthetics. The SWAC Secretariat presented key findings from Africapolis, a geospatial database on cities and urbanisation dynamics in Africa, and presented its analytical work on border cities. Seven panel debates addressed topics such as border twins, the size of border urbanism, border cultures, border crossings, mobility and livelihoods. Rapid population growth is blurring the lines between urban and rural areas. Drawing on 200 000 data points and estimates of the population and size of over 7 600 agglomerations in 50 countries, Africapolis is a powerful tool for understanding urbanisation dynamics. It helps improve the design of territorial and regional integration policies. Participants raised questions about how development partners could better address fast growing rural-urban linkages and provide stronger support for secondary cities. The SWAC Secretariat also presented its analytical work on border cities to identify and evaluate the drivers and obstacles of cross-border co-operation. Three presentations focused on: growth and density, businesses and health, and accessibility and infrastructure in border cities. Key findings have been published in the “Cities” collection of the West African papers series.