"A parish in the Union and hundred of Ruthin, county of Denbigh, 3 miles (NNW) from Ruthin, containing 115 inhabitants. This parish is pleasantly situated nearly in the centre of the fertile and picturesque Vale of Clwyd. It is only of inconsiderable extent, but in the beauty of its situation, and the richness and variety of the surrounding scenery, it is not inferior to any spot of the same extent in this part of the principality. The lands are all enclosed and in a high state of cultivation, and the soil is tolerably fertile."
[ A Topographical Dictionary of Wales, 1833 & 1849, Samuel Lewis]
The parish of Llanychan contains only one township, namely Rhydellteyrn.
It is a very small parish, being less than one square mile in extent.