Talk:List of Welsh principal areas by highest point

height
What is the 'height' above? E.g., above some sea level? Hmains (talk) 05:15, 22 November 2007 (UTC)
 * That would be Ordnance datum (sea level measured at Newlyn) but it's not usual to add that detail. Geopersona (talk) 20:07, 27 January 2024 (UTC)

Torfaen, RCT, Merthyr Tydfil and Caerphilly
The highest points of the first two of these unitary areas are the slopes immediately east of summits which actually lie in adjacent areas. I've tweaked the figure given for one since, as a simple glance at an OS map suggests, it is unlikely to be true (and noting that no references are provided for any of the heights in this list). The highest actual summit within Torfaen would appear to be the north-western outlier of Coity which is labelled as Cefn Coch (574m at OS grid ref SO 2201 0939) whilst the highest summit within RCT appears to be Graig-fawr (558m at OS grid ref SN 9210 9610). In truth, both these names likely refer to the edges of the flattish tops across which they're written and the tops might more properly be referred to as Pen y Cefn Coch and Pen y Graig-fawr. Only referenced names can go in the article though. I've also noted the fact of the highest points of two further principal areas lying on the slopes, southern in these cases, of other higher hills. I've adjusted the figure presented in one case as seeming more likely than the unreferenced estimate previously given. Geopersona (talk) 20:05, 27 January 2024 (UTC)
 * Update - Waun Lysiog doesn't feature at all! Closer examination of the OS map reveals the highest elevation within Merthyr Tydfil county borough to be just to the west of Pwll Mere, roughly 200m west of the high point for Caerphilly - it might amount to 531m. The latter, perhaps 4m higher, is closer to SO 082111 but it's probably technically correct to label it as SO 082110 on this otherwise unremarkable stretch of moorland. The highest actual summit within Merthyr Tydfil CB would appear to be Garn Ddu (462m at SO 0274 1240) (with the nearby and more shapely Cefn Cil-sanws just 1m lower) whilst the highest in Caerphilly seems to be the un-named 442m high northern top of the Cefn y Brithdir ridge at SO 1146 0497 unless the 460m ring contour indicating a rather minor northern top of Mynydd Fochriw is to be counted suggesting an elevation of c.461m at around SO 099048. Though some of this (all of it maybe?, given WP's need for suitable referencing and no Original Research) cannot go in the actual article, I've included these background notes in the hope of assisting any future unearthing of references. Geopersona (talk) 04:40, 28 January 2024 (UTC)
 * But have since added hill-bagging website as a general ref which backs up what I'd added - search county tops/wales. Geopersona (talk) 05:17, 28 January 2024 (UTC)