What is "rubya"

Rubya (or Rubyia) is the site of a Catholic Church mission to the south of Bukoba near the west bank of Lake Victoria in Muleba District, Kagera Region, Tanzania. A seminary was established at Rubya in 1904, one of the first in German East Africa, as it then was. The seminary still operates. There is a cathedral, a nursing school and a district hospital, all operated by the church.