The 31 hotels everyone should stay at in their lifetime, according to the man who tests them out for a living

Every globetrotter has a bucket list of must-travel destinations - but sometimes the hotel is the draw in and of itself.

Philippe Kjellgre, the founder of PK's List, knows this more than most.

Originally the founder of luxury hotel website Kiwi Collection, Swedish-born Kjellgre has written seven travel/hotel books, runs a travel advisory service for high-profile clients, as well as a newly-launched hotel app - and he's currently on an 800 day trip around the world to visit over 1,000 of the world's best hotels across all seven continents.

He was flying from Tokyo to Sydney when he spoke to Business Insider, and says that he has so far visited "most of Africa, all of Asia" and is "now heading [to] the Pacific, then the Americas after that."

The goal? To visit the best hotels on the planet in person so that users of his app know every one has been personally vetted by him.

"I decided to travel for 800 days non-stop, for two and a half years, and I'm on day 400-and-something," he told Business Insider, adding that he's already been to all of the hotels in the past, but "had to go back and prove I've been there."

"I'm travelling the world visiting the hotels, proving it through social media, then adding them to the app," he said.

The app - which costs $99 per year - allows users to search for anywhere in the world and see which hotels Kjellgre personally recommends within their budget.

"You can press call or email and contact them directly," he said, adding that it's "all my research in your pocket."

Kjellgre said he grew up travelling, and had been to about 100 countries by the age of 25. Now, he says he's personally stayed in about 2,000 hotels in 139 countries.

After constantly being asked for advice, he decided to start a bespoke travel advisory service after leaving Kiwi Collection - where he is still a shareholder - a few years ago, and now caters to three tiers of business. The top tier is invitation-only for "ultra-high net worths" including royals, according to Kjellgre, who says they pay him a retainer to help with travel advice and work his connections and access.

He has a team in London and people "scattered all over the world" - and claims to have personal relationships with "about 3,000 general managers in about 330 countries."

Still, he says he's "not the type of person who only stays in super high-end hotels" - although he says "not every hotel is great."

We asked Kjellgre for his pick of the absolute best hotels on the planet that everyone should visit in their lifetime.

Scroll down to see his bucket list selection, ranked in ascending order by the starting cost per night.