The Fukuoka City Museum on the Momochi seafront holds a collection focused on Fukuoka's history as one of Japan's primary gates to the wider Asian world. The museum covers the city's role in Chinese and Korean trade, the Mongol invasions of 1274 and 1281 (which were repelled partly by typhoon storms and partly by the defensive earthworks of northern Kyushu), and the later development of the city under the Kuroda clan.
The gold Han seal is the centrepiece and displayed prominently with good explanatory material. The rest of the permanent collection traces Fukuoka's connections to mainland Asia over two millennia with a substantial range of objects. The building is near Fukuoka Tower on the Momochi reclamation, making it convenient to combine with the tower visit. The museum is large; allow at least 90 minutes. Temporary exhibitions often focus on Fukuoka's contemporary links to the rest of Asia, reflecting the city's current identity as Japan's most Korea-and-China-facing major city.