Hello - I had an idea you folks might want to think about: My wife is of English/Welsh decent and we've wanted to see the U.K. for years. If any of you would be interested in visiting America you might consider a simultaneous vacation. i.e. We could travel to each other's cities and stay in each others houses for a specified period of time (1 week perhaps) We live in the Seatt ...[text shortened]... course, but could save us both a great deal in lodging costs. Send me a PM if you're interested. 🙂
I can offer a bit of advice.
Winter on the fair isles of Great Britain and Ireland is an acquired taste. Please visit from June - September if it is your first time.
I'm not sure what really interests you (nature, urban areas, etc), but I'll give a list of things you might want to do:
White cliffs of Dover - iconic
Glastonbury Tor - the rumoured site of King Arthur's burial, "Avalon".
Cornwall in general - perhaps even a trip to Isles of Scilly?
Stonehenge (this is man-made, but I couldn't classify it under "urban" ).
Snowdonia is breathtaking. I mean really
Anything in the highlands is spectacular and a must-see.
If you can, get to the Hebrides as well.
In general, it's just very green and pretty. You can see Scotland on a clear day from some parts.
Too many smaller towns that are rich in history to list here.
If you are interested in American history, you might want to see the Sulgrave Manor (George Washington's ancestral home) although it's less of a manor and more like a cottage)
If you like tennis, Wimbledon is a must...
Funny, I have my eye on splitting my time between Washington state and the UK when I get my degree. Unfortunately, I cannot take up your offer until I qualify, but I wish you the best of luck.