SillyMilly you have GOT to visit North Norfolk, it is truly awesome!!
I am biased, but I have been to both Cornwall and Northumberland, both lots of times.
Northumberland is surely not to be beaten, and Cornwall has a similar, albeit not as nice (imho) coast as Northumberland. Bays, rocks, cliffs. Whereas Norfolk is something completely different.
And I think Norfolk is much more suited to the 3yo and the 70yo than Cornwall - a lot of the smaller, nicer Cornish beaches have to be reached with a bit of very steep rock paths.
If you stick to the area from Brancaster through to Wells-Next-The-Sea you will get big, VAST, sandy beaches with lots of space.
First and foremost, if you're looking at holidaying in North Norfolk, check out these cottages first -
Blakeney Cottage Company
Sowerbys Cottages
Here's my guide to the North Norfolk Coast -
Brancaster - lovely sandy beach, popular with windsurfers and kiters to the west and families to the east. The sea is never that far away. Has loos and a refreshments / bucket and spade hut. The only downside is that the carpark will get full up at peak times and so you'll have to park in the village and take the very beautiful walk along the coast path.
Nice posh pub.
The Ship Inn
Nice not posh pub. (good pizza)
The Jolly Sailors
Next door is -
Burnham Deepdale - Fat Face store. Big convenience store, petrol station, large cafe. Camp site.
Deepdale Cafe
Nice posh pub. Outstanding sunset views over the marshes.
The White Horse
A mile inland you have -
The Burnhams where Admiral Nelson was born!!!
There's the mega-posh, Burnham Market full of monied, london types. And locals too. But lots of lovely boutiques to wander around.
Then Burnham Thorpe my most favourite place in the world with a lovely little park on the green opposite a nice, pub. You can walk the length of the village through the tiny little stream. In late summer there's a farm selling PYO plums.
The Lord Nelson
Back on the coast road is Burnham Overy Staithe. If you can manage the 20 walk on the coast path across the marshes, you will be greeted with Norfolk's finest beach. Which is basically the furthest western end of Holkham beach, only it's quieter and you can actually see the sea! Samphire to pick in low tide at summer.
Nice pub.
The Hero
Next is -
Holkham home to Viscount Coke and his young family, this beautiful estate encompasses one of the UK's most famous beaches. The Holkham beach is vast. Parking, refreshments hut, no loos. Enjoyed mostly by horse riders and dog walkers. The sea is a long way from your car though!
There's also a wonderful, hotel/pub/restaurant, a fantastic wine shop. You can visit the park where there have deer wandering around on a daily basis, a great adventure playground, beautifully kept gardens, a transport museum and the house to look around. Oh, a lake with various activities too. You'll quiet often see a game of village cricket played on the lawn. Wherever you stay, Holkham is definitely worth a day trip.
Holkham Estate
The Victoria
For a traditional, family seaside holiday, you can't beat Wells Next The Sea. It's quite a sizeable seaside town, a bit posh, a bit tacky - in all the right proportions!!
The beach itself is great for kids. There is a large carpark (although in the summer holidays, and summer weekends expect this to be full by 10:30am) with loos and a great cafe. The beach is large, sandy with colourful beach huts and a big island of sand dunes. When the tide is in little ones can paddle quite safely in a big flat 'pool'. When the tide is out, they'll love playing the mud!!
What not many people do at Wells is take notice of the great pinewoods that back the beach. If you meander through here, you might find a great rope swing and some secret pirate pathways through to the sand!
In the town, there are two lovely pubs around the green. Lots of little seaside type shops, and normal shops the locals use too. There's also a new co-op supermarket.
The Globe Inn
The Crown Hotel
After this the beaches start to become pebble beaches, and not so big. But the towns and villages are just as lovely.
Stiffkey is right on the main coast road. There's not really much to visit here except if you're passing Stiffkey Stores is a really lovely little shop selling all sorts of high quality knick-knacks and yummy coffees etc.
Blakeney is lovely. A tightly-packed town around a harbour. Nice restaurants and pubs. Lots of cottages to rent. But very tight on parking - very few (none that I know of) of the cottages have their own driveway and there is no space to park on the road. There are 2 carparks to use.
Wiveton not really anything here, except the most amazing cafe with sea views. Also a PYO strawberry and raspberry farm.
Wiveton Cafe
Cley is a lovely, lovely place to stay. A windmill. (B&B and cottages) A smokehouse. Nice pub. Lovely deli. Norfolk Wildlife Trust have a bird watching cafe here. Pebble beach, cheap parking.
Salthouse Pebble beach. Nice pub, The Dun Cow.
I'll stop there because I think any further is too far from the best beaches. No point in coming all the way to Norfolk if you're not a short distance from Wells or Holkham, I think.
Places inland to stay or visit are Binham with a large ruined Abbey, Little Walsingham with lots of religious history, a chocolate deli (!!!) and a narrow gauge railway in to Wells, North Creake Abbey a small ruined abbey, little boutique shops, great farm shop and cafe, little ride on tractors for little ones, Holt great cafe/restaurant called Byfords, lots of lovely little independent shops plus shops like Fat Face & Joules - the Duchess of Cambridge has been known to do her antiques shopping here!!
Sorry, this seems a little mad! You'll probably say you've just booked Cornwall!!
I absolutely LOVE Norfolk! We never go away in the summer because nothing beats staying in Norfolk.
So if you any questions at all (or anyone else) PM and I'll answer as best I can.