What is the best travel destination for a family with older teenagers?
MOM can be part of your walking adventure. Does not have to be side by side step by step. She might just be your driver taking you out in the morning and fetching you at night to take you to sleeping place. maybe she is moving your luggage from one sleeping place to the next one. Suggest you let mom participate in a way that is comfortable for Mom AND DAD. Japan is much more than just one very large city. You can explore the countryside if you want. As mom is not a keen walker maybe you also plan for her days activity that is less walking. You ALL do not need to be attached 24/hrs a day. Shall we guess your budget? Length of "vacation " time? Maybe you allow Dad some one to one time with each individual and not just YOU. As an older teenager you should be able to handle a few hours exploring not holding mom or dads hand. You ALL do not have to do EVERYTHING together the entire vacation. Maybe the children can give the Adults some alone time and not behave like jerks released from captivity. You say this is DAD'S time . Suggest you let DAD decide what DAD wants to do. You as concerned caring teenage child do what you can to accomadate dad and other family members to make it as possible as you can. REALLY you just have two options Rural walk in Spain or the Orient in particular the city of Tokyo or Seoul? Wants it to be calming or spiritual.and you expect this in a city of 20,000,000. https://www.youtube.com/watch?v=hNiDd0rAgGU Thousands of shrine places around the planet to give thanks obviously the one in Spain means something to DAD. All you need to know. Not very hard to find some special natural place relatively quiet and away from the hordes of others. Try a National Park. https://www.youtube.com/watch?v=UBq7HAs_ZJY
This trip should really be about your dad and his spiritual wishes should be taken into account. I don't know how much you know about the route to Santiago, but unless you are physically extremely fit, it is very difficult and to walk the whole thing takes several weeks. The whole thing may be too much for him. But you could consider walking part of the way, maybe to one of the shrines where he could give his personal thanks for deliverance, and then meet your mom in Santiago or have her walk a little of the way before the end. I too would not recommend Tokyo if you are looking for spirituality. Major tourist areas in Thailand are also busy (especially Bangkok), but beach holidays are possible if you avoid crowds and it's also a spiritual sort of place if it doesn't have to be Christianity. Ditto India which is both spiritual, welcoming and very diverse in what it has to offer. Bali too but also very commercial. I think it's all about compromise so that each of you gets what you need from whatever you decide on. Enjoy!
Maui. I would recommend Royal Lahaina Resort and Lineage (Please see the attached URL below) http://www.funalysis.net/travel-travel-guide-maui-hawaii-from-a-japanese-viewpoint-2
Peru - Machu Piccu. You don't need to hike it you can take a bus up if you prefer, but when you get up to the city you spend a solid four hours or long walking around so you get a "hike" out of it. It's spiritual. It's impressive. It's amazing. You guys won't forget it.
First, I'd do whatever is on Dad's bucket list. China was on mine and it was awesome. With the teens then maybe any Southeast Asian country. If they are wild then stay away from the stricter ones. I love Philippines. They have some wild destinations and the people are super wonderful Probably the nicest on the earth as far as I can tell.
Maybe a religous part of spain with beaches and good internet connection, the kids or your mom could hang around the beach and relax while if your near a jungle, they have alot of beautiful churches all around