Floating at Casto Marim salt pan spa, Eastern Algarve

Castro Marim salt pans don’t only produce sea salt and flor de sal the traditional way; they’ve also turned a salt water pond into an outdoor spa experience. Here, you can soak in salt while being covered in gooey clay, one of the more unusual things to do in the Algarve.

Note: Accommodation options in the area are listed at the end of this article.

Castro Marim salt production dates back millennia

5,000 years ago, salt was already being produced in the salt pans of Castro Marim, a town in the eastern part of the Algarve, close to where the Guadiana River meets the Atlantic Ocean. The local salinas, as salt pans are called in Portuguese, are one of the oldest in the country. They’ve seen the Greeks, the Celts and the Romans, who used to be paid their wages in sea salt; hence the word salary.

Castro Marim’s more recent history has been intertwined with salt production. The salt pans used to provide the local conserving and canning industry, 70 fish factories in total, with the huge quantities of salt that were needed to preserve the fish. However, when the local fishing industry declined, around 1980, so did the need for salt, leaving the salt pans abandoned.

The difference between salt and salt

The neglected salinas were put into use again in 2000 for environmental reasons. The shallow ponds provide the ideal feeding ground for many bird species that live in the natural park. Eight years later, Luís Horta Correira founded the Água Mãe company, which produces sea salt and flor de sal (a thin layer of flower-like salt crystals that forms on top of the ponds) in a traditional way.

Luís Horta Correira in front of his salinas, Castro Marim
Luís Horta Correira. Photo: Kyle Rodriguez

Flor de sal salt crystals, made the traditional way

Instead of heavy machinery, all the work is done by hand, using wooden rakes and shovels. And that’s where the difference between salt and salt lies.

Normal table salt is harvested by machines, and afterwards heated and cleaned, sometimes with the help of chemicals. In this industrialised process, nearly all minerals are lost. When harvesting the salt by hand, there’s no need to clean it afterwards as you can be more precise, and thus the salt retains all the good minerals.

Beyond salt. Mud between your toes

The salinas of Castro Marim offer more than just salt and flor de sal. In 2015, Luís Horta Correira decided to turn one of the pans into a mud bath that offers a spa-like experience.

His reason? To increase the popularity of Portuguese sea salt and make learning about salt more attractive to the general public.

To be honest, the pond doesn’t look that appealing on first sight. Think a giant muddy puddle on a dirt road after heavy rainfall.

Salinas, Castro Marim, Algarve, Portugal
Salinas, Castro Marim, Algarve, Portugal

Then again, looks can be deceiving and the brown colour is because the bottom of the pond is made out of argila, special clay that softens your skin and contains 80 different minerals. Normally it’s sold in cosmetic spas, but here, it’s freely available to slap all over your body.

Applying the mud at Casto Marim salt pan spa, Eastern Algarve
Applying the mud at Casto Marim salt pan spa. Photo: Kyle Rodriguez

Stepping into the brown water, you’ll feel mud slipping through your toes as your feet will sink into the squishy bottom, all the way past your ankles.

The ‘spa’ salt pan is a bit deeper than the regular salinas to allow for swimming and its salinity is similar to that of the Dead Sea. Let yourself fall and you’ll float comfortably in salty water with a temperature between 29 and 32˚C, depending on the time of day.

The salt also works as a natural exfoliating scrub and the black mud hardens and turns dark grey as it dries in the sun. Just like a regular face mask, it can easily be washed off again.

Salt pans are no ordinary spa

Bathing in a salt pan is certainly an experience. A natural one. Unlike a normal, modern spa, with expensive treatments, mood lighting and luxurious buildings, here the back-to-basics surroundings are made out of wood and clay, blue skies and the sun.

No bubble baths, multiple pools, water jets, steam rooms, saunas or other fancy stuff – it’s just soaking in salt while you’re covered in clay. The only luxury: a bright red pillow to rest your head on. Instead of carefully selected tranquil music playing in the background, you’re listening to the relaxing sounds of the many birds that live in the nature reserve.

One thing, however, is exactly the same: the insanely smooth skin you’ll have after your spa visit.

Also in the Castro Marim area: esparto baskets & birdwatching

Done relaxing in Castro Marim’s salt spa and learning about traditional salt harvesting? Don’t forget to visit Castro Marim itself, with its medieval castle and pretty gardens in Arab-Islamic style. This town is a good place to purchase local handicrafts; it’s famous for baskets and bags that are woven out of esparto grass (you’ll find some examples of them in the mercado municipal building).

With flamingos, storks, slender-billed gulls and about 150 other bird species, Sapal de Castro Marim and Vila Real de Santo António Nature Reserve, the wetland area which also includes the salt pans, is a paradise for birdwatchers.


Great rural accommodation near Castro Marim

If you like the idea of staying in a more rural, traditional part of the Algarve, this part of the Eastern Algarve offers countryside, traditional towns and easy access to Praia Verde beach.

Quinta da Fornalha – Santuario Agroecologico is a working farm that offers a wide range of houses and apartments surrounded by 12 hectares of organic Mediterranean orchards. You get a pool, a private beach and you can pick your own organic vegetables to cook in your kitchen! See the photos.

The delightful hosts at Monte de Malhão offer quality, artistic decor and furnishings an an outdoor pool, hammocks in the garden. Check availability and prices.

The beautifully renovated Compania das Culturas guesthouse makes creative use of the traditional buildings to offer comfortable eco-friendly accommodation with an outdoor pool. Choose an apartment or room to suit.


Or see my ultimate guide to choosing the best Algarve Accommodation for options throughout the region.


  1. Hola! We will be Lagos so hoping we can experi nce the Castro Marim Salt Spa. I am not having much luck finding a site explaining hours and bookings and such. We will be in th Algarves from Oct 12-15 ?☀️ Thanks for such a thorough and interesting read! We are two Canadians exploring for a couple weeks. So excitied!

  2. I always read Enjoy the Algarve and usually share it on Facebook every month so it’s nice to find this post. I’ve passed by the spa and ‘wondered’. Maybe next time I’ll come in. 🙂 🙂

    1. Author

      I often read it too and am thrilled to be able to share their experiences with my readers. If you’re interested in knowing more about the Algarve, it’s well worth subscribing to.

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