。
Hōryū-ji is the oldest wooden building in the world.
Literal
Hōryū-ji [topic-は] world [possessive-の] oldest wooden-structure-[assertion-である]
A fact about one of Japan's most famous cultural treasures. 法隆寺 (Hōryū-ji) is a Buddhist temple complex in Nara, founded in the early 7th century. 最古 (さいこ) = 'oldest, earliest' (最 'most' + 古 'old'). 木造建築 = 'wooden construction/architecture'. である closes with the formal written copula.