I'll kick things off!
I'm from the UK - I have an English mother and a Scottish father - so I'll introduce interesting places for photography in England and Scotland. I'm going to skip the capital entirely. Perhaps another member living in the city can focus their answer on London.
Shout-outs to well-known places that all photographers should have on their UK itinerary:
Stonehenge - a famous prehistoric monument and a UNESCO world heritage site. It's mind-boggling to ponder how they moved the stones between 4 - 5000 years ago. Silhouetted shots in late evening light are fun to experiment with.
The Cotswolds - gloriously scenic region of thatch-roofed medieval villages and rolling hills. It spans 6 counties. Very photogenic.
Oxford and Cambridge - the architecture of the university colleges is wonderful. Groups of students punting on the river make for great images.
Lake District National Park - arguably the most beautiful place in England for landscape photographers.
Edinburgh - I was there last in summer 2015 and was blown away by the Gothic architecture. A very special city.
I believe these to be lesser-known gems, equally worth visiting to the iconic places above:
The Lizard - Incredible coastline at the southernmost tip of the English mainland. Everyone heads to Land's End around the corner. Don't. Lizard Point is much more beautiful and fewer people.
North Somerset coast - This is quite a drive, passing through Exmoor National Park. I don't know which I'd rather be; the driver or the camera-toting passenger. Both very fun.
Durham & its Cathedral - Beautiful old city in the north of England, near Newcastle. Head to the amazing 900+ year old cathedral, a UNESCO world heritage site and one of the best examples of Norman architecture anywhere. Be warned - photography is prohibited outside of regular specialist photography evenings. I should know... I was chastised by a member of the clergy there for taking pictures during the day. Best to come along on one of the designated evenings.
Isle of Mull & Isle of Skye - Beautiful, unmissable islands off the west coast of Scotland. The fishing village of Tobemory on Mull has very photogenic houses along the harbour-front, each painted a different colour. Skye has the epic Old Man of Storr - a hill featuring a rock formation so unique and iconic, it has become a kind of pilgrimage for landscape photographers who know about it.
Hope you enjoyed reading this. Now I'd love to hear about your country (or state/province/city). Other PhotoBlog members in the UK: please add places I missed. Please don't feel pressured to write as much as I did.
Looking forward to reading what people come up with.