I think Turkish Hammams were a revelation to my Western sensibilities.  When I traveled to Turkey, I was traveling with a high school friend now living in London, and her friends joined us.  One of her friends was Turkish, with her family living in Istanbul.  So four of us trotted off to the Hammam in a local neighbourhood.  We entered the female side - the men had their own space.  We went into a room to leave our things and then were ushered in our bathing suits a large circular room reminiscent of a sauna.  We sat in the heat, removing most of our bathing suits (our bottoms remained, though I do not believe a requirement) and allowed our bodies to relax.  One by one we were called over to a large round table where a woman cleaned us using soap and water.  The experience itself can vary (I've heard some male workers can be quite rough), but overall an absolutely fantastic cultural experience you have to try if you get the chance.  

With several different pools with a variety of temperatures and benefits and many services to choose from, Szechenyi was awesome.  My regret is we didn't get to stay longer.  The main building is beautiful and ornate and there are so many different nooks and crannies to explore.  Definitely worth a few hours if you find yourself in Budapest.  One warning - there are very few private changing rooms.  The Europeans just don't care.  

Bath is a great get a way from London and has been designated a UNESCO Heritage Site for it's history with Roman Baths.  The Thermae Bath Spa is an excellent stop as it's the only natural thermal spa in the UK.  There are several experiences and floors to explore, include the open air roof top pool, as well as many additionally priced spa services.  It's relaxation and a history lesson all wrapped up in one.

This is an experience I've not done, but doesn't it sound cool?  Apparently beer has some unique properties to it that benefit your health.  Soak in a beer bath, drink unlimited Czech beer.  This is definitely on my radar my next trip to Prague.

Located roughly 30 minutes outside of Krakow, Wieliczka Salt Mine is both a tourist attraction and a spa (you can visit here and never take advantage of the spa facilities as well).  You can even stay at the underground salt facility.  Whether you want to stay for the day for a few weeks, there are a number of options available.  And if sleeping 135m underground in a salt mine isn't your thing, there are above ground accommodation options as well.

The Blue Lagoon in Iceland seems to get a lot of the travel buzz, but this little gem should be the top of everyone's list.  A Natural Spring, Laugarvatn Fontana is a quaint lake side thermal spa that houses 4 outdoor pools and if memory serves, 4 saunas (both wet and dry).  You can even go take a dip in the lake if you'd like, but there are warnings to not swim too far as parts of the lake are actually boiling.  The Spa also serves up a delicious lunch, worth the money.  There's even a soup only version of lunch that is for those trying to watch pennies.  The spa also bakes lava bread - bread that cooks underground for 24 hours and as God as my witness it is like nothing else on earth.  For a surcharge you can go out to experience the phenomina, or come early, as the bread is served with lunch.  The thermal spring is included in several Golden Circle tours so whether self-driving or on a group tour, it's definitely possible to fit this gem into your Iceland visit.  Note that there are no spa services here (e.g. massage), but that shampoo and conditioner are provided for your showers.  You are required to shower naked and there is only one private shower stall, so if you come with a group, plan your departure for the change room accordingly if you need privacy.

It's not every day a place is dubbed a spa town, but that's exactly what Karlovy Vary is.  It seems like the town is a hot bed for health tourism.  In fact the bed is so hot, there are numerous Spa Houses in town, which feature accommodation and wellness treatments all in one facility.  Here, you'll find everything from oxygen therapy, cryotherapy, carbon dioxide bags and baths, electrotherapy and a whole host of different massage styles - there are over 50 types of services offered,   The town is also host to 15 Colonnades and springs, many of which are open to the public to drink from.  

If you are an architecture enthusiast, this is likely the spa trip for you.  Nestled in the Alps in what seems like the middle of nowhere, Therme Vals has a modern flare that compliments its natural surroundings.  Pools range from 14C to 42C, there are 3 relaxation rooms and a whole list of services and treatments to choose from.  And with the Swiss Franc at time of writing coming in at 1.28 for ever 1 CAD, Switzerland has a better exchange rate than the EU or the UK, making visiting her a bit more affordable than it's ever been.

Technically in Asia (most of Turkey is), this cool landscape is about an hour's flight from Istanbul (and Turkey has some super cheap flights connecting you across the country).  Translated to "cotton castle" from the Turkish, Pamukkale is a thermal spring created by the travertine left over from the water flow.  There are 17 springs in total ranging in temperature, even as high as 100C.  Along with Hierapolis, Pamukkale is a World Heritage Site.

As Karlovy Vary is a testiment to, Health Tourism is a growing industry.  There are several luxury spa resorts across Europe that you can indulge in, creating a unique spa experience to anything else on my list.