It's the trip-of-several-lifetimes.
Unfortunately, you'll probably have to work for several lifetimes to pay for it.
There is no doubt that this will be one of the most thrilling, memorable and inspiring experiences that a couple could ever wish for.
A British web company has begun marketing a two-year super-luxury jaunt taking in the world's 962 UNESCO World Heritage Sites for the, ahem, bargain price of $1.5 million per couple.
The indulgent adventure will theoretically wind its way through 157 countries.
Travellers who are lucky enough to be able to leave their jobs, mortgages and financial cares behind will be guided around sites including the Taj Mahal in India, Stonehenge, Egypt's Pyramids of Giza, Easter Island, China's Forbidden City, Machu Picchu, the Grand Canyon, Petra in Jordan, the Acropolis and the Vatican City.
Australia's 19 UNESCO sites will also be covered, including the Ningaloo Coast, the Great Barrier Reef and Kakadu National Park.
The company behind the trip, VeryFirstTo.com, stipulates that all destinations must be “safe and pragmatic” at the time of visit.
This would rule out certain sites that the Department of Foreign Affairs and Trade currently advises against travel to, such as Sudan and certain regions of Bangladesh and Indonesia.
Part of what will make the trip - which has yet to be purchased - so expensive, is that it will be done in luxury, with travel in business class or superior when possible.
Accommodation includes luxury hotels such as the Hotel George V in Paris, the Plaza in New York, the Cipriani in Venice, The Ritz-Carlton in Moscow and the Taj Mahal Palace in Mumbai.
Guided tours of the sites are included in the price, as is a $7300 donation to UNESCO, presumably to round the price tag off to an even 1 million pounds.
Founder of Veryfirstto.com, Marcel Knobil, told The Daily Mail his company was for people "who like to be the very first to have and do wonderful luxury things whatever the price tag".
Other decadent experiences offered by the site include the chance to wake up surrounded by more than one million rose petals for $102,000, the world's most expensive Christmas dinner ($182,000 for four) and the chance to have your marriage proposal made into a national TV advert, for almost $200,000.