Hi Anorak
I lived in Cleethorpes 7 years ago.
Stuff to do, places to eat etc:
The Lost Shepherd - restaurant( 01472602303 56 Thrunscoe Road, Cleethorpes ) Fantastic little place, need to book in advance
Steel's Cornerhouse - excellent fish and chips (01472692644 Market Street, Cleethorpes)
Granary Restaurant - nice pub/restuarant on a little canal just outside town centre.
(01472346338 Garth Lane, Grimsby)
Lincoln Castle - near to Fishing Museum. Used to be the ferry between Grimsby and Hull across the Humber before the Humber Bridge was built.(01472242945 Alexandra Dock North, Grimsby)
To do:
Usual Beach/funfair/pier in Cleethorpes
Pleasure Island for the kids.
Walk along the sand dunes to Humbersstone (there is a cycle path all the way)
Seaview Street in Cleethorpes - nice little old shops.
Best Shopping in Freshney Centre, Grimsby
Fishing Heritage Museum is a must.
Walk around the fish docks is interesting
Peoples Park in Cleethorpes nice for a picnic.
If you can get out to the wolds , Louth is a lovely market town (good Thai restaurant there too)
Hope you have some lovely weather!! Enjoy.