claim: The Challenge XXX: Dirty 30 is not a season of a TV series.
evidence: Inaridai Sword , also known as Inaridai No. 1 Kofun tumulus Iron Sword -LRB- 稲荷台一号墳出土鉄剣 Inaridai Ichi-gofun Shutsudo Tekken -RRB- , is an ancient iron sword excavated in Inaridai No. 1 Kofun tumulus in Chiba Prefecture , Japan .. sword. sword. Chiba Prefecture. Chiba Prefecture. Japan. Japan. The sword was probably forged in Kinai region in the 5th century and buried with the deceased person in the late of the century .. sword. sword. Kinai. Kinai. Its silver-inlaid inscription is the important source of the Japanese domestic politics in the period .