This is a third-grade teaching unit on large cities (megalopolises) in the United States. The components of the unit are: (1) a content outline, (2) unit goals, (3) unit objectives, (4) activities, (5) unit evaluation, and (6) bibliography. The content of the unit focuses on defining a megalopolis, noting what can be found in it, its special characteristics and problems. Unit goals address the content areas and include skills of library research and group projects. Attitudinal goals for the unit are to appreciate the cultural benefits of living in a megalopolis and to appreciate cooperative work. Objectives are coded to these goals and their respective activities. Activities for the unit include discussions, films, brainstorming, drawing, library research, small group projects, graphing, writing, and field trips. The unit evaluation is parallel with the unit goals and objectives, and assesses a variety of written work, group projects, and class participation, in addition to including a unit test. A 10-item annotated bibliography is appended and includes both student and teacher resources. (JDH)