Self driving a safari in Africa, driving up real close to one of the Big 5, but not close enough to risk turning myself into a delicious meal.
Volunteering in a wildlife conservation project in South Africa.
Learn a new language in a foreign country, polishing up my Spanish in Barcelona will be first on my list. (Well, visited Barcelona in January 2016 and practised some Spanish there)
Embark on a working holiday in New Zealand. (Ain’t happening but New Zealand campervan trip took place in July 2017!)
Explore the culture-rich Japan. (First trip to Okinawa in January 2018!)
Do the classic backpacking Europe trip, but with more emphasis on eastern Europe. (Cleared UK, parts of Spain, Athens)
Catch the Northern Lights in Iceland and Norway. (Cleared Iceland in September 2016!)
Do a adventure glacier expedition in Patagonia, Chile.
Travel from Thailand to London by train, via the Trans-Siberian Railway.
Do the Mount Everest Base Camp Trek.
Visit the South Pacific islands before tourism sets in extensively.
Visit Artic Circle and Antartica sometime. (Cleared the Artic Circle in Sweden during March 2016)
I hope this list grows slower than my travel milestones list.
You need these for long road trips. Cheers! Salud! Sláinte! na zdrowie!