What even counts as a sauna these days? Well, according to Wikipedia, saunas are defined as "a small room or building designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these facilities."

Related: 10 Cat Lover Destinations In The USA

Historically, the first saunas are thought to have been in Finland but those were pretty different from the saunas used today. Though you can still find pretty unusual ones around the world. Some are in fact sought out by travelers due to their uniqueness. Not every sauna is built the same and here are ten that are definitely stranger than most.

10 The Tram Sauna In Milano, Italy

This sauna was combined with a train car! It sits in a spa complex,  TermeMilano spa, where it has its own tracks to sit on. The sauna has kept a lot of the original carriage features as well, such as its pitched roof and tram windows. Inside there are benches and hot coals which enough space to sit about ten guests.

So how this this tram sauna even get made? Well, local designers created it and they did so with the thought that public transport should be more relaxing. Unfortunately, the city did not approve of a tram sauna that actually transported people so instead is it part of the TermeMilano spa.

9 Gondola Sauna In Lapland, Finland

Saunas are a must-do when visiting Finland, the homeland of saunas. There is one that is particularly strange, a sauna that is also a gondola at a ski resort village in Ylläs

Related: 10 Best Movie Locations Worth Traveling To

It is not just for show either. You can ride it as a 2km-long ski lift from the base station to the top of Ylläs,  which is about 800m above sea level.

8 The World's Largest Public Sauna In Sandhornøya, Norway

The world's largest public sauna is located on a remote beach in Norway. It is a location where travelers can relate and sweat with a view of the Arctic Sea. It is so big that it can fit about 150 people inside. It is able to fit that much because the pyramid-shaped room has amphitheater style seating.

The sauna was created for SALT, which was the world’s first Arctic arts festival in Sandhornøya.

7 Burger King Sauna In Helsinki, Finland

Back to the land of saunas, Finland outdid the strangeness again with a Burger King themed sauna. Yes, you can have a coke, whopper, and fries while you sweat. It opened as the world's first fast food sauna in 2015.

Related: 10 Strangest Public Baths In The World

The facility includes a 48-inch TV, a 15 person sauna, and a media lounge with another TV, Playstation 4, a shower room, locker room, and restroom. It costs about 280 dollars to have the place for three hours.

6 Hockey Stadium Sauna In Helsinki, Finland

Watching a hockey game does not get more luxurious than this.

Related: 10 Small Towns In Europe That Should Be On Your Travel Bucket List

Helsinki, Finland does not only has the Burger King sauna but a sauna in a hockey stadium! It is part of Skybox 408, which seats about 72 people and the sauna can fit a lucky group of 20. It is definitely not cheap though. It costs about  $2,822 to rent the place for a single night.

5 Ice Sauna In Lapland, Sweden

These may be considered strange, but not in Finland. Finland has multiple places where you can sit in a sauna that is encased in ice and/or snow. Everything in these saunas are made of ice and snow except for wood benches to sit on.

Related: 10 Strangest Museums In The World

So it it like an igloo. However, how does it not melt? Well, it does. These saunas do not last forever and even get an expiration date. Some only last a couple sessions before they have to be reconstructed.

4 Underwater Sauna In Gothenburg, Sweden

Have you ever been into a sauna and been like "I wish they have leaned into the theme of water more?"

You are in luck because there are saunas in the world that even go underwater. One such sauna is located in Sweden. Its walls are made of glass for viewing the underwater landscape. You can feel wet from sweating while looking out at fish or see people swimming. There are few records of this particular sauna in English, so it is a hidden gem for travelers. Not to mention, the fish are rather big and hard to miss!

3 Sauna Bus In Ruka Resort, Finland

The Ruka Skiing Resort has sauna buses that allow you to sweat while on the road. It travels between the nearest airports, so you can sweat out your flight fatigue. It is tailored for tourists so that they can take in the landscapes.

Related: 10 Hidden Springs In Florida You Need To Check Out

Do not worry, as they also make stops along the way so that guests can cool off outside in the snow.

2 Grotto Sauna In Ontario, Canada

This private sauna in Ontario is on the shore of Lake Huron. It has been known as one of the most beautiful places in the world to see the sunset, at least according to National Geographic. Its unique curved design is based off of the national formation that occurs in waterside grottos, which are underground chambers that were made by the flow of water currents. So it is not only a sauna, but a pretty impressive architectural marvel.

Related: The 10 Strangest Beaches In The World (& Where To See Them)

Most of the structure is made of cedar wood, which was chosen for its aroma, warm rues, and adversity to rot. The sauna is fittingly named, "Grotto." Unfortunately though, it is not open for tourists since it is privately owned.

1 Salt Cave Sauna In Den Bosch, The Netherlands

This sauna is conveniently located in a sauna resort. As its name suggests, the walls are made of Himalayan salt. As pretty as the cave is, the salt it is not just for show. The Himalayan salt walls of the sauna are known to have health benefits such as regulating blood sugar.

The sauna is so visually stunning that is has become a pretty popular image on Pinterest. The real question though is how many curious people do you think have tried to lick the walls? We do not recommend trying that.

Next: 10 Of The Most Unbelievable & Amazing Coral Reefs