Afon Glaslyn
Glaslyn Gorge
Location
Country	Wales
Counties	Gwynedd
Towns	Porthmadog
Villages	Bedgellert
Physical characteristics
Source	Glaslyn
• coordinates	53°4′14″N 4°3′58″W / 53.07056°N 4.06611°W / 53.07056; -4.06611
Mouth	Tremadog Bay
Length	16 miles
Basin features
Tributaries
• right	Afon Colwyn
Waterbodies	Llyn Llydaw Llyn Gwynant Llyn Dinas Llyn Bach
Bridges	Pont Aberglaslyn Pont Croesor Pont Britannia

Afon Glaslyn (Welsh for 'River Glaslyn') is a river in Gwynedd, north-west Wales. While not of great significance in terms of its length (about 16 miles (26 km)), it is one of Gwynedd's primary rivers, and has greatly influenced the landscape in which it flows.

It has its source in Glaslyn, a cirque lake on the flanks of Snowdon. It is joined by Nant Traswnant which drains Pen-y-Pass and by Nant Cynnyd before entering a lake, Llyn Gwynant. The river then flows through Llyn Dinas before entering the village of Beddgelert. In the middle of the village it is joined by the substantial tributary, the River Colwyn which drains the south-western flank of Snowdon. The much enlarged river flows down past Gelert's grave before tumbling down into the Aberglaslyn Pass. This is a small rocky gorge close to the main road which provides easy public access to a most picturesque piece of Snowdonian scenery.

Passing through Pont Aberglaslyn, the river emerges from the gorge into the relatively flat agricultural land of Tremadog and Porthmadog. This wide flat valley – now called Traeth Mawr – was once the estuary of the Glaslyn before the Porthmadog Cob was created. This sealed off the mouth of the estuary, enabling the land to be reclaimed. Once the river has crossed under the railway line, it meanders in large pools and marshes before eventually passing through the tidal sluices on the Cob at the south-eastern end of the town of Porthmadog, and from there into Tremadog Bay. Further south, the River Dwyryd also drains into Tremadog Bay.

The first pair of breeding ospreys in Wales nest at Pont Croesor about 4 miles (6.4 km) upstream from Porthmadog where the RSPB have set up observation facilities.^[1] They first bred in 2005 and have returned every year since.

Fishing on the Glaslyn up to Beddgelert is controlled by the Glaslyn Angling Association.

• Aberglaslyn Hall

Wikimedia Commons has media related to Afon Glaslyn.

• www.geograph.co.uk : photos of Afon Glaslyn

v t e Gwynedd
Principal settlements	Bala Bangor Barmouth Bethesda Blaenau Ffestiniog Caernarfon Criccieth Dolgellau Ffestiniog Harlech Nefyn Porthmadog Pwllheli Tywyn
Towns and villages	Aberangell Aberdaron Aberdesach Aberdyfi Abererch Abergeirw Abergwyngregyn Abergynolwyn Aberllefenni Abersoch Abertrinant Afon Wen Anelog Arthog Beddgelert Bethania Bethel Bethesda Betws Garmon Bodferin Boduan Bontddu Bontnewydd Botwnnog Bryncroes Bryn-crug Brynrefail Buan Bwlch-derwin Caeathro Capel Celyn Carmel Carnguwch Ceidio Chwilog Clwt-y-bont Clynnog Fawr Corris Uchaf Corris Croesor Cwm-y-glo Deiniolen Dinas Dinas Dinlle Dinas Mawddwy Dinorwig Dolbenmaen Dolmelinllyn Dwygyfylchi Edern Efailnewydd Eisingrug Fairbourne Friog Frongoch Ganllwyd Garndolbenmaen Garneddwen Gellilydan Glasinfryn Groeslon Llan Ffestiniog Llanaber Llanaelhaearn Llanarmon Llanbedr Llanbedrog Llanberis Llandanwg Llanddeiniolen Llandegwning Llandudwen Llandwrog Llandygai Llanegryn Llanelltyd Llanengan Llanfaelrhys Llanfaglan Llanfair Llanfihangel Bachellaeth Llanfihangel-y-Pennant Llanfihangel-y-Pennant, Dolbenmaen Llanfrothen Llangelynnin Llangian Llangwnnadl Llangybi Llaniestyn Llanigian Llanllechid Llanllyfni Llannor Llanrug Llanuwchllyn Llanwnda Llanymawddwy Llanystumdwy Llithfaen Llwyndyrys Llwyngwril Maentwrog Mallwyd Mellteyrn Minffordd Morfa Bychan Morfa Nefyn Mynydd Llandygai Mynydd Nefyn Mynytho Nantlle Valley Nantmor Nasareth Nebo Pant Glas Pen-y-meinl Penffridd Penisa'r Waun Penllech Penllyn Penmaenpool Pennal Penrhos Penrhyndeudraeth Pentre Gwynfryn Penygroes Pistyll Pontrug Porthdinllaen Portmeirion Prenteg Rachub Rhiwddolion Rhos-y-gwaliau Rhosgadfan Rhoshirwaun Rhoslefair Rhostryfan Rhyd Ddu Rhyd Rhyd-uchaf Rhydyclafdy Sarn Meyllteyrn Soar Tal-y-llyn Talsarnau Tal-y-bont (near Bangor) Tal-y-bont (near Barmouth) Talysarn Tanygrisiau Trawsfynydd Trefor Tregarth Tremadog Tudweiliog Tywyn Waunfawr Y Felinheli Y Ffor Y Fron Y Rhiw
Education	Bangor University Coleg Harlech Coleg Meirion-Dwyfor Coleg Menai Schools
Castles and forts	Caernarfon Castle Castell y Bere Criccieth Castle Dolbadarn Castle Harlech Castle Fort Belan
Rivers	Afon Aber River Adda Afon Artro Afon Cegin Afon Cwmnantcol Afon Daron Afon Dwyfor Afon Dwyryd Afon Dysynni Afon Fathew Afon Glaslyn Afon Llyfni Afon Mawddach Afon Ogwen Afon Rhythallt Afon Seiont Afon Tryweryn
Islands	Bardsey Island Ynys Gifftan Ynys Gwylan-fawr Saint Tudwal's Islands
Topics	Parliamentary constituencies Churches Places Schools SSSIs Country houses Listed buildings Grade I Grade II* Registered parks and gardens History Lord Lieutenants High Sheriffs Museums Public art
Geography Wales

52°55′N 4°07′W / 52.917°N 4.117°W / 52.917; -4.117