Conwy is a walled medieval town where the stone towers of the castle loom over the river. You can walk the full circle of the high walls for free. This gives you a great view of the slate roofs and narrow streets. My top tip is to find the smallest house in Great Britain near the quay. The scent of salt and fresh mussels drifts from the harbour where red boats bob on the tide. Near the square, the old house of Plas Mawr shows how the rich lived long ago. Local shops sell dark honey and heavy fruit cakes. Life here is tied to the massive walls and the busy waterfront. It is a striking choice for a heritage break with dogs welcome on the paths around the bay.