Bryn Hyfryd is in Harlech. It sleeps ten but it's a four bedroom cottage with a couple of sofa beds, so it's best for a flexible sort of group. It has a 4 Star rating.
It's detached and made of stone. You can see the sea and the dunes from the front windows. I wouldn't say breathtaking, but it's a very good view. The lounge has an open fire. There's a dining table that seats everyone.
The stairs are cottage stairs, just so you know. There are two bathrooms.
Facilities are straightforward: parking, wifi, TV, washing machine, dishwasher. Bedding and towels are provided. You can bring up to two dogs.
Harlech beach is about a fifteen minute walk downhill. It's a good, long sandy beach. The castle is closer, maybe a ten minute walk. It's a proper castle on a big rock. The views from the top are worth the climb.
If you want to drive, Portmeirion is about twenty minutes north. It's an odd, colourful Italianate village. Snowdonia is half an hour east if you fancy a mountain walk or taking the train up Snowdon. The Llyn Peninsula is a nice drive for a coastal afternoon.
If you're planning trips, the Visit Wales site is useful, and National Trust Wales lists their nearby properties like Plas yn Rhiw.