Family Search have an interactive map called "England and Wales Jurisdictions 1851" showing parish (and other) boundaries with optional background maps such as Ordnance Survey. There is also a Search facility, do read the guidance notes to get maximum benefit from this useful resource. See here for further background information to assist in the interpretation of this data
You can see pictures of Llanddewi'r Cwm which are provided by:
You can see the
administrative areas in which Llanddewi'r Cwm has been placed at times in the past. Select one to see a link to a map of that particular area.
Victorian Powys for schools site - Map of Llanddewi'r Cwm in 1888 with a link to an 1833 map:
Plan of the parish of Llanddewi'r Cwm in the County of Brecon. 1840. William Fosbrooke, Bridge Street, Hereford, valuer and surveyor. First class map based on a new survey. Voluntary agreement. Commutation dated 01.11.1839. Shows construction lines, hill-drawing, waterbodies, houses, rock outcrops, field boundary ownerships, building names, boundary trees and mill; lake named. Apportionment omits most field names. 3,101 acres commuted. Apportionment by holding. Land use details given in apportionment schedule. Tithe rent charge £121.4.0d (£80.16.0d Sarah Price and George Anderson; £40.8.0d Varnum Pococke
You can see maps centred on OS grid reference SO035486 (Lat/Lon: 52.127254, -3.411079), Llanddewi'r Cwm which are provided by: