This raster layer contains urban land use and land cover data for Ulaanbaatar, Mongolia in 1990. Categories of urban land use represented in these data include: urban, nonurban, water and other. Urban land cover, or urban extent, is typically measured by the total built-up area (or impervious surface) of cities, sometimes including the open spaces captured by their built-up areas and the open spaces on the urban fringe affected by urban development. Urban land is occupied by urban uses that include all land in residential, commercial, industrial, and office use; land used for transport, parks, and public facilities; protected land, and vacant land. Land in urban use does not include cultivated lands, pasture lands, forests, farms and villages, intercity roads, and nature areas. These data are part of the Atlas of Urban Expansion. The Atlas of Urban Expansion provides the geographic and quantitative dimensions of urban expansion and its key attributes in cities the world over. The data and images are available for free downloading, for scholars, public officials, planners, those engaged in international development, and concerned citizens. The global empirical evidence presented here is critical for an intelligent discussion of plans and policies to manage urban expansion everywhere. This resource provides both the conceptual framework and, for the first time, the basic empirical data and quantitative dimensions of past, present, and future urban expansion in cities around the world that are necessary for making minimal preparations for the massive urban growth expected in the coming decades.