We are traveling via rental car to England, Wales, and Scotland for 2 weeks and want to see many castles, museums, ruins, historical sites, etc. There are various types of passes that provide discounted entry to such places, but we don't know which one to buy and whether to buy it before we leave Seattle or when we arrive in U.K. --any advice will be greatly appreciated. We are senior aged but I don't know if you have to be a U.K. citizen to get local senior discounts.
The English Heritage pass for overseas visitors will be your best bet:
http://www.english-heritage.org.uk/visit/overseas-visitors/
English Heritage maintains many of the castles, ruins and historical sites whereas The National Trust is geared more towards stately homes, natural sites, gardens etc. We have membership with both and find that we use our English Heritage pass more than the NT one. A lot of the NT nature sites are free entry anyway.
Here's one for England.
https://www.hrp.org.uk/
This one is for Scotland.
https://www.historicenvironment.scot/
We enjoyed our National Trust Pass because we enjoy architecture antiques and art. It is so much fun to see all this in a home that combines it all in one place. They do have many more locations in England and Wales than other passes and they include parking. You can join as members if you want to support their efforts. Scotland has separate passes. You can compare all of these on the Visit Britain site. Being from the Northwest we have lots of beautiful scenery and nature available...but how many castles and great estates do we have?
Many Welsh historic sites come under CADW =http://cadw.gov.wales/?lang=en
Other historic buildings are under the National Trust.
Wow, such great information! Thank you so very much!
It may depend on when your visit is.
In very general terms, I tend to think of English Heritage buildings as often roofless and without furniture; and National Trust tends to be furnished with a roof.
For castles, ruins and historical sites I agree that EH may be better for you.
I think that senior is sometimes defined in the US as starting at 50. Most places in the UK will use 60 or 65. Most places will refer to the discount as either a Concession (abbreviated Conc.) or Pensioner and won't care what country you are from. It isn't anything to get too excited about, the discount is usually just small percentage or few pence or pounds.
Generally, for most museums, the question is moot because the vast majority of museums are free to all (donations always gratefully accepted), especially in London and the bigger towns and cities.