Possible Clues:

• Castle here? King's in blooming check!
• Town in North Wales, noted for its ruined castle
• Small town with castle overlooking Cardigan Bay
• Its men sung, as king facing execution heartily went to church
• Castle very hard outside — clear inside needs repair
• Difficult having bottom pinched by lewd fellow somewhere in Wales
• Rush with companion round lake somewhere in Wales
• Ffordd Pen Llech in ____ has recently been recognised as the world’s steepest residential street
• North Wales town noted for its ruined castle overlooking Cardigan Bay
• Town with a castle north of Barmouth