Coast has been showing here for (?) three seasons now. It is soothing, and there are some lovely bits: the hidden sea-cave full of technicolour corals that noone but marine biologists ever see, that can only be visited on two days a year; the sculpture of ten thousand statues on the long lonely strand-beach, all looking half-lost out to sea; the place where the cliff has fallen into the sea for two thousand years, leaving a hilltop-fort half suspended; the grotto-altar built by a odd nobleman, carved almost inaccessibly into a cave in a seacliff.
But this is interspersed, as shewhomust says, by Bright Young Things doing experiments on which beach's sand is best for making sandcastles. It's a little frustrating, but worth it for the moments that feel like they walked straight out of a Susan Cooper book.

(I am personally more addicted at present to Ancient History of Britain. You have the same archaeologist presenter, with his charming accent, and he's solo presenter. It's one of the most joyful archaeologist shows I've seen, & as beautifully shot).