Bauamt: an isometric city builder on a square grid. You paint streets, lots and parks. Every lot grows a building by the same rules as the city on the Nachtschicht home page: eight kinds of night with their own footprint, colour and roof detail, four size classes, and a seed that decides the small differences. Streets join into lanes with tram rails and street lamps; parks get trees and a lamp. The whole city is stored in the address, so a link shares the layout. The toolbar picks the tool, the kind and the size, undoes and redoes, clears, rolls a random city, changes the hour of the sky, fits the view, saves an image, copies a link and opens the help. Arrow keys move a tile cursor and Enter paints.