Answer the following question: The Cheonseongjinseong is located on Gadeokdo Island Gangseo-gu Busan Metropolitan City the Republic of Korea. Gadeokdo Island area was strategically important being located at the end of the sea route from Tsushima Islands of Japan to Busan and Jinhae and thus had been vulnerable to Japanese marauders from ancient times. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
Answer:
Building