Penmaenbach and Penmaenmawr are the names given to the two headlands (big 'n small: -mawr, -bach) that abut the Irish Sea, the area between which includes the secluded vally where TyF is.
This is a locals secret.
Not much use at high tide - the water laps the sea wall by the tunnel although left there is sand and shingle
and some nice grass - but a large expanse of sand at
other times to eg let the dog roam, or just to get away from the crowds.
You can walk here from Dwygyfylchi beach, and also across the sands (at low tide) from Conwy Morfa.
Of historical interest: the stagecoaches of old travelled these expanses of sand around
Penmaenbach when the tide allowed, this being quicker and easier than over the Sychnant Pass.
Going east on the A55 from Pen. there is an obvious layby (arrowed) before the headland (immediately after the traffic lights gantry that spans the carriageway) . Backtrack a little to a tunnel (arrowed in pic) under the railway to access the beach. Getting here on foot directly from TyF means crossing the A55 - at your own risk!