Port area
Kaikyou Yume Tower
Standing 153 meters tall, the Kaikyou Yume Tower features an observation deck in the glass sphere at the top, with panoramic views over the city and the Kanmon Straits. Internet access is available at the Yamaguchi International Exchange Association Tu-Su 10AM-8PM.
Near the Kanmon Bridge, there is a marker for the site of the Battle of Dan-no-ura. The Bombardment of Shimonoseki is also commemorated nearby — there are a few replica cannons, positioned at the point where the allied troops came ashore. Now perfectly willing to do trade with foreign barbarians, the cannons will puff out a bit of smoke and a 'boom' in exchange for a few coins.
Shunpanro Hall
The Treaty of Shimonoseki, which ended the First Sino-Japanese War, was signed on this site in 1895. There is a small museum built in 1936 dedicated to the treaty with period furniture and some relics. It's next to an expensive ryokan see Sleep.
Akama Jingu
A shrine dedicated to the loser of the Battle of Dan-no-ura, Emperor Antoku of the Heike Clan, whose tomb is on the premises. Aside from the impressive vermilion gate, look for Hoichi Hall and the statue of Mimi nashi Hoichi Earless Hoichi, who features in a well-known ghost story by Lafcadio Hearn.
Sumiyoshi-jinja
A complex of shrines dedicated to the Shinto gods of the sea and sailing, with a main hall that has been designated a national treasure. There are displays of ancient scrolls, metalworks, and other relics. It's about a 20 minute walk from Shin-Shimonoseki Station, and can be reached from the Ichinomiya bus stop.
The tiny island of Ganryujima, off the southern coast, was the site of an epic samurai duel between Miyamoto Musashi and Sasaki Kojiro, two master swordsmen. Kanko Kisen runs ferries from Karato Pier ten minutes, ¥1000 round-trip.
At 268 meters high, Hinoyama offers good views of the Kanmon Straits. There's a ropeway to the peak if you'd prefer not to hike ¥200/400 one-way/return, and a pleasant park at the top. And since there's not enough of them in the city below, you'll find a fugu restaurant (http://www.fukunoseki.com...) and souvenir shop 9AM-6PM as well. Buses run from JR Shimonoseki Station.
Kaikyokan Aquarium
Dolphins, penguins, and sea lions join over 100 varieties of pufferfish, with four floors of exhibits about marine science and shows throughout the day. It's right next to the Kanmon Bridge, and buses run directly there.
Chofu area
The Mori clan lived in this well-preserved castle town and samurai quarter in the northeastern part of the city, which makes a nice, atmospheric walk at any hour. Buses run to stops for Matsubara and Joka-machi 25 minutes, ¥340. There is a Chofu station on the San'yo Main Line, but it's a bit of a walk from there to the attractions.
Shimonoseki Municipal Archaeological Museum
Displays of Kofun and Yayoi-era archaeological finds as far back as 500 B.C., including a few outdoor mounds, pit dwellings, and tombs.
Chofu Mori Residence
Built in 1903 by the ruling Mori family, this palatial estate and its gardens were deemed worthy of a visit by the Emperor Meiji a few years later.
Kozan-ji
Although it is Japan's oldest zen temple and a national treasure, founded in 1327, Kozan-ji has been known through the years as a place for warriors to rouse themselves before battle. The Chofu Museum Tu-Su 9AM-5PM, ¥200 is on the grounds of the temple, with displays about the Meiji Restoration.
Chofu-teien
An elegant Japanese garden built for a chief retainer of the Mori clan, encircled from the outside world by trees and a small mountain.
Iminomiya-jinja
This modest temple comes alive between August 7-13, when a festival is held in honor of the Emperor Chuhai and Empress Jingu — particularly wild at night.
Nogi-jinja
A shrine dedicated to General Nogi Maresuke, a key leader in the First Sino-Japanese War and the Russo-Japanese War. Ashamed by the number of lives lost under his command in the latter, Nogi petitioned the Emperor Meiji for permission to commit seppuku. His petition was denied; the Emperor told Nogi that "if you insist on killing yourself, let it be after I have departed from the world." When the Emperor did depart, seven years later, Nogi was still ready; he committed seppuku shortly after the Emperor's funeral entourage left the palace. As a result, Nogi came to be seen as a symbol of the end of the samurai code.
Karato area
Former British Consulate
Built in 1906, with the small Shimonoseki Ijinkan Museum inside and a tea house in the back.
Nabe-cho Post Office
Built in 1900, this is the oldest post office still in service in Japan.
Meiji-era foreign buildings mix with with modern ferroconcrete in the Karato area, which is illuminated at night.
Former Akita Company Building
This European-style building originally housed the offices of a shipping company. There's a particularly nice Japanese garden on the roof; the first floor has sightseeing information and a gift shop.