On FindmyPast there are a number of images of marriages dated about 1790 taking place in a parish in Denbighshire - but they do not seem to know which parish it is, in the transcription the 'place' is blank!
The marriage which particularly interests me took place on 30 Jan 1790 between Thomas Jones of Ruabon Parish, bachelor, son of John Jones, Collier by Anne his wife, aged 20 and Mary Edwards of this Parish, spinster, daughter of Edward Edwards, Shoemaker, by Mary his wife, aged 23. They were married by the vicar Edward Jones.
In addition to Ruabon, other parishes mentioned by name (in other marriages shown) and so, presumably, not 'this Parish' are Llantysilio, Wrexham, Corwen and Bryn Eglwys.
Does anyone know where this marriage took place?