The Mill is down a small lane near Tregaron. It's a wing of a much older building. The bit you're in is from the 13th century, I think. It feels old, but not dark. The main room is big and open.
It sleeps four. Two upstairs bedrooms and one bathroom. It has a 4 Star rating, which is good. The place is comfortable. There's a wood burner, which works well. We leave wood for you.
The facilities are all there. Washing machine, dishwasher, WiFi, TV. The parking is right outside. The entrance and downstairs are all on one level, so it's fine if you have mobility issues or a pushchair.
You can bring one dog. The garden is enclosed, mostly gravel and slate, so it's practical.
Tregaron is two miles away. It's a small, proper Welsh town. There's a good pub on the square that does food. A couple of shops, a butcher, a co-op. It's handy. The Walkers Are Welcome status means the footpaths are well-kept.
Right on the edge of town is Cors Caron, the big bog. It's a Natural Resources Wales reserve. The boardwalk lets you walk right out into it. You'll see red kites there, almost always.
You're on the edge of the Cambrian Mountains. The roads through them, like the one to Abergwesyn, are really quiet and beautiful for a drive.
Aberystwyth is about half an hour by car. It's a university town with a long promenade, a ruined castle, the usual stuff. The steam railway from there up to Devil's Bridge is worth a trip. The coast that way has several good beaches.
The other way, also about half an hour, you've got Aberaeron. Very colourful harbour town. And New Quay, which is a proper little fishing port. You can get boat trips from there and you often see dolphins.
Useful links: Visit Wales for general ideas and National Trust Wales for some of the bigger local places.