One less ugly, crumbling parking lot; one more nice Denver building. For the last several years, the Civic Center Office Building, a gleaming new twelve-story edifice, has been rising at the north end of Civic Center Park. When it opens this summer, the structure, designed by David Owen Tryba with RNL Design, will provide badly needed office space for the City and County of Denver. The building -- especially the main tower, a contemporary neo-modernist confection with dramatically curving walls of aluminum and glass -- will also provide a nice complement to the rigidly rectilinear 1949 city-owned international-style Annex I, which will be connected to it by a large atrium. The new building's height allows a graceful transition between the relatively low profile of the monumental public buildings of the Civic Center and the much taller commercial skyscrapers just behind it in the central business district.