The area is part of the foothills of the Preseli Mountains rising to an altitude of 248 metres and is dissected by deep valleys of the Tâf and its tributaries.

[3][4] In the 20th century the main road through the community, which links Cardigan, Ceredigion in the north to Tenby, Pembrokeshire in the south, was designated the A478.

The hamlet has a public house (the Cross Inn), a petrol station incorporating a supermarket, a vehicle repair business and a number of domestic dwellings.

On 13 May 1839, the tollgate at Efailwen was the first to be attacked in what would later become known as the Rebecca Riots, an uprising by poor farmers to abolish what they believed was unfair taxation.

[5] Efailwen has a school (Ysgol Beca) serving surrounding settlements, a roadside eatery and a number of domestic dwellings.