River Dyfi in the context of "Dyfi Hills"

Gwynedd (Welsh: [ˈɡwɨnɛð]) is a county in the north-west of Wales. It borders Anglesey across the Menai Strait to the north, Conwy, Denbighshire, and Powys to the east, Ceredigion over the Dyfi estuary to the south, and the Irish Sea to the west. The city of Bangor is the largest settlement, and the administrative centre is Caernarfon. The preserved county of Gwynedd, which is used for ceremonial purposes, includes the Isle of Anglesey.

Gwynedd is the second largest county in Wales but sparsely populated, with an area of 979 square miles (2,540 km) and a population of 117,400. After Bangor (18,322), the largest settlements are Caernarfon (9,852), Bethesda (4,735), and Pwllheli (4,076). The county has the highest percentage of Welsh speakers in Wales, at 64.4%, and is considered a heartland of the language.

Machynlleth (pronounced [maˈχənɬɛθ] ) is a market town, community and electoral ward in Powys, Wales and within the historic boundaries of Montgomeryshire. It is in the Dyfi Valley at the intersection of the A487 and the A489 roads. At the 2001 Census it had a population of 2,147, rising to 2,235 in 2011. It is sometimes referred to colloquially as Mach.

Machynlleth was the seat of Owain Glyndŵr's Welsh Parliament in 1404, and as such claims to be the "ancient capital of Wales". However, it has never held any official recognition as a capital. It applied for city status in 2000 and 2002, but was unsuccessful. It is twinned with Belleville, Michigan.

Ceredigion (Welsh: [kɛrɛˈdɪɡjɔn] ), historically Cardiganshire (/ˈkɑːrdɪɡənˌʃɪər, -ʃər/, Welsh: Sir Aberteifi), is a county in the west of Wales. It borders Gwynedd across the Dyfi estuary to the north, Powys to the east, Carmarthenshire and Pembrokeshire to the south, and the Irish Sea to the west. Aberystwyth is the largest settlement and, together with Aberaeron, is an administrative centre of Ceredigion County Council.

The county is the second most sparsely populated in Wales, with an area of 688 square miles (1,780 km) and a population of 71,500; the latter is a decline of 4,492 since the 2011 census. After Aberystwyth (15,935), the largest towns are Cardigan (4,184) and Lampeter (2,970). Ceredigion is considered a centre of Welsh culture, and as of the 2021 census, 45.3% of the population could speak the Welsh language.

Aran Fawddwy is a mountain in southern Snowdonia, Wales. It is the highest point (county top) of the historic county of Merionethshire (for local government purposes, it lies within the current council area of Gwynedd). It is the highest peak in the Aran mountain range, the only peak in Wales outside North Snowdonia above 900m, and higher than anywhere in the United Kingdom south of Northern Snowdonia. The nearest small settlements to the mountain are Dinas Mawddwy to the south, Llanymawddwy to the southeast, Llanuwchllyn on the shores of Llyn Tegid (Bala Lake) to the north, and Rhydymain to the west. The nearest settlements with around 2,000 people are Bala and Dolgellau. On the eastern slopes of Aran Fawddwy is the small lake named Creiglyn Dyfi, the source of the River Dyfi. Its sister peak is Aran Benllyn at 885 metres (2,904 ft). There is also a middle peak: Erw y Ddafad-ddu.