Where'd they film that?

The Swans Centre for Innovation on Station Road in Wallsend.  This is the exterior location for the fictional Northumberland and City Police.

First and foremost, this is a private residence.  Please be respectful of the owners!  The cottage is located on Holy Island, Northumberland.   

If you think of Holy Island’s shape as a chicken drumstick, the Snook is its handle and the first part of the island you drive alongside as you cross the causeway. It is part of the Lindisfarne Nature Reserve and is home to dunes and salt marshes.

The Snook can either be reached on foot from the village via the dunes or by car. The turning to the Snook is about halfway between the start of the causeway and the island. You then follow a dirt road, and there is a small parking area where you can stop. Note that the dirt road is full of deep potholes and has not been mended in a while. Drive carefully.

If travelling to the Snook by car, remember to check the tides, as the entire stretch between it and the island can get submerged during higher tides.

There are two lone houses in this location: Snook Tower and Snook House, dated early to mid 19th century.  

As viewers have suggested, living on the island would make it challenging for Vera to get to work urgently. Then again, fiction is fiction, and the creative license allows the series to show the island’s beautiful scenery.  --as per visitlindisfarne.com