“The Building Zone,” for children 2-6 accompanied by an adult, children learn about building trades through play. 10 a.m.-4 p.m. Mondays-Saturdays, 11 a.m.-4 p.m. Sundays, through Sept. 30, National Building Museum, 401 F St. NW. $3 per person and includes entry to the Building Zone. 202-272-2448.
National Garden tour, education technician Alex Torres leads a walking tour and gives tips for using native plants and improving your garden; sunscreen, protective clothing and water suggested. 10:30 a.m. Thursdays, through Sept. 20, U.S. Botanic Garden, 100 Maryland Ave. SW. Free. 202-225-8333.
Hillwood garden tours, docent-led tours exploring the history of the gardens and identifying plants. 10:30 a.m.-12:30 p.m. Tuesdays-Saturdays, 2:30 p.m. Sept. 16, Hillwood Estate, Museum and Gardens, 4155 Linnean Ave. NW. $15; age 65 and older, $10; ages 6-18, $5; 5 and younger, free. 202-686-5807.
Cooking figs demonstration, gardening specialist Adrienne Cook and nutritionist Danielle Cook Navidi cook fresh figs; recipes given to participants. Noon-1:30 p.m., U.S. Botanic Garden, Conservatory Garden Court, 100 Maryland Ave. SW. Free. 202-225-8333.
Cathedral iconography tour, for age 10 and older, docents examine the iconography of the building’s sculpture, stained glass and needlework, which illustrate events in the nation’s history. 3 p.m., Washington National Cathedral, Front Nave, Wisconsin and Massachusetts avenues NW. $10. 202-537-6200, www.nationalcathedral.org or tickets.cathedral.org/public/show.asp?shcode=253.
Megan Jean and the KFB concert, gypsy, circus, American roots and avant-garde music. 6 p.m., Kennedy Center, Millennium Stage, 2700 F St. NW. Free. 202-467-4600.
Apps for artists, Nancy Freeman teaches how tablet and smartphone software apps can create electronic art. 7 p.m. Thursdays, through Sept. 27, Hill Center at the Old Naval Hospital, 921 Pennsylvania Ave. SE. Free, registration required. 202-549-4172 or www.hillcenterdc.org/home/programs.
E-book reader help, a librarian demonstrates how to read or listen to free books and other library media using an e-book reader or smartphone; search for works in the library database and check out library materials with the e-reader; bring a device and library card number. 7 p.m., Southeast Library, 403 Seventh St. SE. Free. 202-698-3377.
Kayak tour planning for Anacostia River, Anacostia River Watershed Society’s Lee Cain discusses a planned tour for the public. 7 p.m., Hill Center at the Old Naval Hospital, 921 Pennsylvania Ave. SE. Free, registration required. 202-549-4172 or www.hillcenterdc.org/home/programs.
Artist’s computer game talk, Kristoffer Zetterstrand discusses how computer games have influenced his painting. 7 p.m., Smithsonian American Art Museum, McEvoy Auditorium, Eighth and F streets NW. Free. 202-633-1000. americanart.si.edu/calendar/event.