Originally constructed in 1576, Maruoka Castle (丸岡城, Maruokajō), is one of just twelve castles remaining in Japan that have survived the post feudal ages with their castle keeps (donjon) intact. The relatively small, 3-story keep is considered the oldest in the country and exhibits a few interesting design features such as stone roof tiles and a hidden level that is invisible from the outside. The castle is also known by the nickname "mist castle" which comes from a legend about thick mist hiding the fortification from approaching enemies.
Maruoka Castle stands on top of a small hill in the plains north of Fukui City. The interior of the wooden structure is preserved and unfurnished save a few information displays and a diorama of the castle on the lowest floor. A set of extremely steep wooden stairs lead up to the floors above, which visitors can scale with the aid of ropes hung from the ceilings. Those who make it all the way to the top are rewarded with panoramic views of the surrounding plains and the castle park below.
The castle keep is the only major structure left standing. The former castle grounds surrounding the keep are now a public park with a small museum that displays a some arms, armor, and household items related to the former lords of Maruoka Castle. The grounds also feature over 400 cherry trees that typically bloom from early to mid April. An annual cherry blossom festival is held during the first three weeks of April during which the trees are lit up in the evenings by over 300 paper lanterns.
Take a bus from Fukui Station bound for Honmaruoka (本丸岡) and get off at Honmaruoka bus stop (40 minutes, 640 yen, 2 buses/hour). The castle is about a 5-10 minute walk northeast of the bus stop. Alternatively, take a train along the JR Hokuriku Line from Fukui to Maruoka Station (15 minutes, 240 yen, 2-3 departures per hour) and transfer to the same bus there (15 minutes, 200 yen, departures every 1-3 hours).
By rental car, the castle is about a 30 minute drive from Fukui Station. Free parking is provided next to the castle.