By Antoinette Radford
BBC News
Extreme question isn't for the feint-hearted. Kari-Matti Valtari would know.
He has been arrested aggregate times and held successful detention successful war-torn nations, but has seen everyplace from St Eustatius to the Savage Islands*.
So wherefore does helium support doing it? "It's to conscionable like-minded people," helium tells the BBC.
He has a goal: to question the full world. And that extremity has landed him, astatine the clip of writing, successful tenth spot connected the "Most Traveled Person" (MTP) person board.
MTP is an online assemblage that unites utmost travellers. It boasts astir 30,000 members and exists for radical to comparison their adventures, successful a bid to go "the astir travelled person".
But seeing the full satellite - arsenic per Most Traveled People - conscionable got harder for Kari-Matti and different utmost travellers.
The MTP founder, Charles Veley, was inspired to make it aft the Guinness Book of Records declined successful 2000 to judge his ain attempts to beryllium the world's astir travelled idiosyncratic - and required a third-party to adjudicate.
"It felt similar I had completed the marathon successful the Olympics... it felt similar I had done each that. Come into the stadium and each the judges had gone location and determination was nary 1 there," helium said.
In 2005, erstwhile MTP was founded, Mr Veley started with a database of astir 573 countries and territories to visit.
That fig accrued to astir 1,000 successful the pursuing years, arsenic existing places were divided into further parts. And, arsenic of this year, the database has been updated again - to 1,500 antithetic locations.
The enlargement by MTP meant radical who had been to everyplace - oregon astir everyplace - successful the world, present person a full caller acceptable of places to visit.
For instance, the antheral connected apical of the person board, Germany's Michael Runkel, has visited a specified 1,306 of MTP's 1,500 locations.
The MTP enlargement leans connected enactment from different question community, NomadMania, which divides the satellite into 1,301 regions, based connected "area, population, section position and different factors".
Within the UK, for example, determination are 30 antithetic regions, including: England - Yorkshire and the Humber, Jersey, and Lundy - a tiny land disconnected the south-west of England.
One of the caller regions connected the MTP database is the South Pole - present listed arsenic abstracted from the assorted Antarctic regions.
Previously, travellers could assertion they had visited astir Antarctic regions by simply walking astir the South Pole. Now, they person to navigate the full continent.
The summation was based connected consultation with utmost travellers, and Mr Veley said radical had been receptive to the alteration - and looked guardant to having much destinations to visit.
But question betwixt these areas is not simple.
Around 2.4% of planetary CO2 emissions travel from aviation - and galore regular travellers trust connected planes to travel.
While some Mr Valtari and Mr Veley said they effort to trim their emissions successful different ways - similar driving electrical cars - they don't contradict the interaction their question has connected the environment.
"I bash deliberation astir it, but I mean… what tin you do?" Mr Maltari said. "If you person an impulse to question you cannot precisely locomotion everyplace truthful you bash person to fly."
But erstwhile it comes to utmost travel, boats tin beryllium much utile than planes. The joint-least visited spot successful the world, according to MTP, is the Entrecasteaux Reefs - a obstruction reef successful New Caledonia successful the South Pacific.
*St Eustatius is simply a tiny Dutch land successful the Caribbean; the Savage Islands a Portuguese archipelago without a imperishable population.