![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/2/29/Ffynnon_Sarah_-_geograph.org.uk_-_125404.jpg/640px-Ffynnon_Sarah_-_geograph.org.uk_-_125404.jpg&w=640&q=50)
Ffynnon
From Wikipedia, the free encyclopedia
Tarddiad neu fan lle mae dŵr yn codi o'r ddaear ydy ffynnon; twll yn y ddaear, fel arfer.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/2/29/Ffynnon_Sarah_-_geograph.org.uk_-_125404.jpg/320px-Ffynnon_Sarah_-_geograph.org.uk_-_125404.jpg)
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Awyrlun_dron_o_ffynnon_Dyfnog_-_aerial_drone_photograph_of_St_Dyfnog%27s_Celtic_Well%2C_Llanrhaeadr-yng-Nghinmeirch%2C_Denbighshire%2C_Cymru_%28Wales%29_17.jpg/640px-Awyrlun_dron_o_ffynnon_Dyfnog_-_aerial_drone_photograph_of_St_Dyfnog%27s_Celtic_Well%2C_Llanrhaeadr-yng-Nghinmeirch%2C_Denbighshire%2C_Cymru_%28Wales%29_17.jpg)
Tyfodd rhai trefi yn ystod y 19g o amgylch ffynhonnau iachusol, trefi megis Llandrindod ym Mhowys gan y credir eu bod yn iachusol.