godan verb (-ru)
go down to Kyushu
Fixed expression using 下る (to go down, away from the capital) specifically for traveling to Kyushu. The verb 下る implies movement from a central area (historically Kyoto/Tokyo) to a more remote region.
来月、仕事で九州へ下ります。
Next month I will go down to Kyushu for work.
彼は大学を卒業した後、
After graduating from university, he went down to Kyushu and got a job.