What is the fine-grained topic of the following text: The “play and learn” motto by the telecommunication company DTAC, designed by Australian firm Hassell, is evident in the 62,000 square foot 20-story structure which includes a circular library amphitheater, indoor running track, table tennis tables, indoor football pitch, concert and performance spaces, and a roof terrance that overlook’s Bangkok’s beautiful skyline. Only return the topic.
DTAC Headquarters Design by Hassell