To me, Oita is an amazing place that will always be in my heart. In the Spring of 2014, I spent four months in Oita-ken as an international exchange student at Ritsumeikan Asia Pacific University. Oita-ken has many lovely towns, such as Beppu, Hita and Kitsuki. Each town has its own special sights and sounds; they will be great memories for you, just like they were for me.
(Photo of Beppu-wan at early evening, taken from the Ritsumeikan Asia Pacific University campus)

Beppu (別府) is well known for its onsens. However, I like Beppu most for its beautiful bay, which is best viewed from its mountains. Jumonjibaru Observatory (十文字原展望台) in Beppu was voted as one of Japan's top 100 night view spots (日本夜景百選). The bay looks pretty in the day, and looks even more beautiful at night. You can view the amazing Beppu-wan via the Beppu Ropeway, at the Beppu-wan service area or at the Jumonjibaru Observatory.
(Photo of Beppu-wan on a foggy night, taken from Beppu-wan service area)

I like Hita (日田) for its unforced and quiet charm, which emanate humbly from its relaxed streets. Hita's Mameda Town (豆田町), which consists of entire stretches of well-preserved old Japanese buildings, is home to numerous traditional craft and souvenir shops. I spent hours browsing through all the craft stores, simply because each of the craft items displayed were so intricate and unique. I believe you will spend a fruitful afternoon browsing the shops too!
(Photo taken at one of the many traditional craft stores in Mameda Town)

The best time to visit Hita is in Spring, around late May, as Hita City celebrates its annual sightseeing season with a bang - literally - with a stunning array of fireworks. Known as the Hita River Sightseeing Festival (日田川開き観光祭), it features two consecutive nights of fireworks along the Mikuma River that flows through Hita. More than 10,000 fireworks, which make up an hour-long show, are set off to commemorate the festival. What I enjoyed the most was their "fireworks waterfall", where the river glowed with its reflection of the fireworks.
(Photo of the first day of the 2014 Hita Sightseeing Festival, taken from the riverbank of the Mikuma River)

Kitsuki (杵築) is famous for the slopes (坂) that can be found throughout the rustic and traditional town. Much of the town is preserved in its original form, making you feel that time has slowed, or even stopped, as you stroll through its quaint streets. Kitsuki strives to be "the castle city where you want to walk wearing a kimono"; visitors wearing a kimono are granted free entry to all cultural attractions in Kitsuki.
(Photo of school children on their way home, taken from one of the slopes in Kitsuki).

In addition to the three towns described above, Oita-ken also consists of other lovely towns - such as Saiki and Yufu. Yet in my opinion, Beppu is the most charming town of Oita-ken. My favorite spot in Beppu is Lake Shidaka (志高湖畔), a tranquil lake located in the mountains. In spring, Lake Shidaka becomes a great spot for cherry blossom viewing (花見), while in summer it become a joyful camp site for families. Just simply walking around Lake Shidaka gives an overwhelming sense of 開放感 - best translated as "a feeling of openness" - that has left me wanting to visit the lake again.
(Photo of Lake Shidaka at late afternoon, taken in early summer)

I would love to visit Oita-ken in Kyushu once more, as I believe that there are still many amazing places that I have yet to discover, as well as many dear memories that I would be able to forge there. If you ever have the opportunity, please do visit Oita-ken!

(Photo of Lake Shidaka at late afternoon, taken in early summer. The reflection in the water is complete serendipity - no edits or filters have been added)