[citation needed] The parish church of St. Catwg (Cadoc) is ancient but heavily restored (with adult baptismal font) in the Victorian era.

[2] Caerphilly County Borough Council also has its main offices in the community of Gelligaer, being at Penallta House in the Tredomen area of Ystrad Mynach.

[5] When elected parish and district councils were established under the Local Government Act 1894, Gelligaer was given a parish council and included in the Gelligaer and Rugos (or Rhigos) Rural District, which covered the parts of the Merthyr Tydfil Poor Law Union within Glamorgan that did not have urban authorities.

Gelligaer Urban District Council comprised 21 councillors including a chairman and the first elections were held on 30 September 1908.

The council, like other urban districts, was responsible for sanitation, sewerage, housing, streets, cemeteries, libraries, parks, and the licensing of public entertainments.