Here's Hawthorne House in Amble. It's detached, so no one on the other side of the wall. The garden is fully enclosed.
It sleeps eight in four bedrooms. There are two bathrooms. It's got a 4 Star rating, so it's well equipped and comfortable. It's a solid house for a group.
The living room has one of those decorative flame effect fires. It looks nice but it doesn't give off heat, just so you know.
You've got a dishwasher and a washing machine. Bedding and towels are included. There's on-site parking and WiFi.
It's about a 15-minute walk down into Amble itself. There's a small beach and a working harbour. They do boat trips from there. The Sunday market is good. There's a fish and chip shop and an ice cream place on the harbour. You can rent one of the little beach huts.
You can walk along the coast road to Warkworth village. It's very pretty. Warkworth Castle is there. The coast from here north is an Area of Outstanding Natural Beauty.
For a bigger day out, Alnwick Castle is about ten miles away. Alnmouth train station is a few miles down the road. You can get to Newcastle, Durham, or Edinburgh from there reasonably easily if you fancy a city trip.
Useful links for planning: Northumberland National Park and Northumberland Coast AONB.