My in-laws live just outside Louth – I think Rogerthecat has summed it up quite well.
My 6yo likes Mablethorpe for the fun fair and the beech train, but other than that it’s a hole.
Sutton’s a quieter seaside town.
Anderby Creek is probably the nicest spot they’ve taken us to. Not a lot there but has a nice, endless, white, sandy beech with shallow water for paddling.
Donna Nook is good for seal watching, in fact I think this is about the time when they all come up on the shore to have pups.
Last time we visited I decided I’d rather leave the family at the in-laws and rode to my folks’ house in N. Yorks 😉 Found plenty of quiet country lanes for road riding and if you head for the Wolds rather than the coast it’s prettier and hillier than I expected it to be.