Ongyr Isaf 1851 Cens, Rhongur Isaf 1841 Cens, and probably Rhongyr 1819 GFB xli. The uncertain first el. Rhongyr could, in view of the earlier forms given above and those in 4.39, <yr + ongyr, being the W, d.a. and the W, n.m., 'spear' (DWE), now obs. (GM), with the addition of an -h- reflecting a dial. form. The second el. isaf> dial. isha, isa, is the W, adj., 'lowest, lower (of two) (GPC) showing this site's position relative to the other of the same (4.39). The actual sig- nificance of this interpretation is impossible to verify today, unless a topographical feature, not apparently obvious, is implied. Formerly a farm holding until the 1970's, the house is now used as an outdoor pursuits centre. 4.39 RHONGYR-UCHAF (OSM), so named 1891 OS6, 1830 OS, is Rhongyr Uchaf Brych XVI, 70, Ongar Uchaf 1911 HPD 5, Ongur ucha 1879 ERB, Rhongyr Ycha 1819 GFB 1 and probably Tir pen y ffynon otherwise Tir y Rongyr 1579 DP. Rhongyr, v. 4.38, + uchaf W, adj., 'highest, higher (of two)' (GM) > dial. ucha, ycha, the last el. showing its position relative to the other of the same. The earliest form makes reference to the proximity of Ffynnon Ddu. The house and most of land of this holding lie outside the Com. boundary, but the name is listed here for convenience. 4.40 ST CALLWEN, so named BW 321, is Capel Callwen 1911 HPD 18, 1891 OS6", 1804 HB Map Capel Callwen (disused) & St Callwen s Church 1905 OS6" Callwen Chapel 1879 ERB, 1840 CPB 15 Capel Cellwen 1830 OS Capel Calwen 1765 Kitchen, location incorrect with Capely Garreg (sic) in its place Cappel Callwen 1774 EHE, 1829 SR Capel Calwen 1578 Saxton Chapelle of Stradwallen parish of Glentawy 1553 CPB 117 Chapell callid Ystradwallen 1548 CPB 115 church of Glintawe 1552 HMBII,6 The origin and the form of this name are uncertain. Perhaps as a first step it would be as well to question as doubtful Theophilus Jones's interpretation of Callwen as being a corruption of Cellwen 'Fairwood' and describing the surrounds (HBIV, 145). Moreover, the identity of Callwen as a saint is uncollaborated in early sources, especially as some of the earliest forms (ibid) throw doubt on the present orthography; cf also CPB 137. If the latter is the more correct, it is plausible that Callwen < Wallen, Gwallen which is attested as a pers.n. in a W tract Boneddyr Awyr: Nobility ofthe Heroes where she is listed as Mam Rhun ap Maelgwn, Gwallwenferch Afallach (EWGT 91). If the last mentioned is