On Sept. 22, 2 to 4 p.m., discover how to make strong, tall towers at this Play-Well Teknologies workshop. Celebrate the engineering feats of skyscrapers and design structures that that should be added to our nation’s capital. $25. For ages 6, up. Adult companion required. National Building Museum, 401 F St. NW. 202-272-2448. nbm.org.