This resource includes two images and one lesson plan that each inspire discussion surrounding different customs and sources of meaning for Tisha B'Av:
Destruction of the Temple Postcard, 1903 is a great supplemental resource when teaching Megillat Eicha.
Tisha B'Av Postcard, 1903 depicts synagogue attendees seated on the floor during Tisha B'Av services.
Move Yom HaShoah to Tisha B'Av, 1965, is a lesson plan that features a letter to the editor of a newspaper arguing why Yom HaShoah should be part of Tisha B'Av, rather than its own separate day of remembrance.