The All-Japan Tower Federation has designated October 1st as "Observation Day" (Tenbo no Hi)—a tradition established in 2006. The name is derived from the Japanese word *tenbo* (observation/view): the character *ten* (展) is associated with the number 10, while *bo* (望) is linked to the number 1 (represented by the shape of a *bo*, or "stick/pole"). Each year, this day is marked by the distribution of special merchandise, and on the preceding evening, towers across the country feature unique, celebratory illuminations.

On the day itself, visitors to the observation decks at participating towers received a complimentary two-color printed towel (available while supplies last). The towel features illustrations of 20 different towers along with the Federation’s logo. Its convenient size makes it perfect for everyday use, as well as for outings or sports activities!