My wife and I will be in the west country of Ireland and thenon to Wales, northern England and Scotland this May/June. Should we by passes to national trust sites and if so which one? I have seen the foreign visitor passes, there are some options. Any thoughts?
You will have to do the maths and decide which works best for you. You need to decide if you only want it for this trip, or if you will return and if you can get benefit from a one year membership; do you want to buy it in the US and pay in dollars or get it when you get here and hand over pounds? Do you want/need US tax deduction?
Have you looked at The Royal Oak Society which is the US supporting organization of the National Trust with full benefits and a dual card option with full tax deductability?
Or various tourist versions of the National Trust card here...
With either choice you can be happy in Northern Ireland (not Ireland), Scotland, Wales and England...
You may also be interested in English Heritage sites. They tend to be the more ancient places in Britain such as Stonehenge and others that need preservation rather than restoration, although there are other buildings that are still habitable and newer. It really depends on what you want to see. The National Trust and English Heritage websites are searchable by region to give you an idea of the different properties they care for.