In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Llansannan like this:
LLANSANNAN, a village and a parish in St. Asaplh district, Denbighshire. The village stands on the river Aled, amid picturesque scenery, 8 miles W by S of Denbigh r. station; is a resort of tourists and anglers; and has a post office, under Abergele, Denbighshire, a good inn, and fairs on 18 May, 17 Aug., 26 Oct., and 30 Nov. ...
The parish comprises 14,973 acres. Real property, £5,989. Pop., 1,256. Houses, 277. Dyffryn-Aled is the seat of P. W. Yorke, Esq. Much of the surface is waste upland. The Aled, in the upper part of its course, through the S portion of the parish, traverses a narrow dell; makes two highly picturesque falls, called Llyn-yr-Ogo and Rhaiadr-rhyd-y-bedd; and is overlooked by very romantic scenery. A circle of about twenty-four artificial holes, is in a hill, and bears the name of BwrddArthur, or Arthur's Round Table. The living is a vicai.age in the diocese of St. Asaph. Value, £412.* Patron, the Bishop of St. David,s. The church is dedicated to St. Sannan. There are chapels for Independents, Calvinistic Methodists, and Baptists. W. Salesbury, one of the translators of the Welsh New Testsment, was a resident.
GB Historical GIS / University of Portsmouth, History of Llansannan, in Conwy and Denbighshire | Map and description, A Vision of Britain through Time.
Date accessed: 26th April 2017
Click here for more detailed advice on finding places within A Vision of Britain through Time , and maybe some references to other places called " Llansannan ".