A beautiful beach walk eventually leads to one of the UK's last Little Tern colonies at the Long Nanny.
Access is not as simple as in other places. No 'park the car and be amidst it in seconds' option here. There are two parking options. The first at the North end of the bay, in Beadnell, offers a stall that does excellent coffee and bacon sandwiches at the weekend. The second is just North of High-Newton-by-the-Sea and, as far as we know, has no coffee or sandwiches stall.
Public transport wise - it's a struggle. There is a bus from Alnwick that stops in Beadnell; it goes every hour (until 6pm) and takes just under an hour. Sunday service looks rather absent.
You should aim to visit between late May and early July; mid June is probably the best bet to see nesting birds.
Let's assume you're approaching from the North, perhaps after a visit to the Farne Islands from Seahouses.
Ignore the inland footpath as suggested by your Ordnance Survey map. It mostly leads through a caravan site. Instead, from the car park, go straight on to the beach and walk along that instead. There should be plenty of eider on the sea to keep you company on this section.
As you approach the inlet in the centre of the bay, sensible National Trust signs will ward you off the beach and into the dunes. Look out for stonechat here - it's the perfect place for them and there should be plenty. Follow the excellent signposts towards the reserve from this point. If you're visiting later in the day, keep an eye on the fields inland of the path; we happened across a Barn Owl over them the last time we were in the area.
As you approach the reserve, take the leftmost path to a wooden platform next to a shed like structure. There will almost certainly be a ranger and a telescope on top to help identify it. All the rangers have good chat, some of them are also excellent birders. If the terns are on nests then it should only be the work of a minute or two to find one. In more recent years, the colony of Arctic Terns right next to the hut may provide equally good entertainment.
If you're a touch early in the year and you've just got a big bunch of terns sitting on the beach - don't give up hope. The little terns will tend to flock together and the size difference between them an the more prevalent arctic terns should make it possible to pick them out, even without the aid of a 'scope.
Once you've satisfied yourself that little tern has been seen, the other potential attraction is the nesting ringed plovers; the cuteness factor of the chicks is astonishingly high.
Our friends in the North describe the Ship Inn as the best pub in the world. Book in advance if you intend to eat there, mind.