|Location Map ( geo)|
|Distance:||6.1 miles (9.8 km)|
|Route outline (key)|
The B4415 is a rural B-road along the Lleyn Peninsula in western Caernarfonshire.
It starts on the B4413 in the area of Nanhoron and Bodlondeb. The road heads north along the narrow valley of the Horon River through the hills. Near the watershed, the B4415 turns easterly and crosses to Rhyd-y-clafdy. After skirting the marshes it goes over the top of a ridge before descending to cross the River Rhyd-hir.
The road now enters the village of Efailnewydd. It ends here, on the A497.