Urban density is an inevitable issue for our cities. As more and more people move into urban areas, we need to know how to do density right and make it welcoming on a human scale. We report from the annual Council on Tall Buildings and Urban Habitat conference, which this year has the theme of ‘Humanising High Density’, and we discuss the rerelease of a book from the 1920s extolling the virtues of a busy, bustling city.