When my family and I temporarily moved to Santander, I dreamed about finding a great gym and I…read morefound it at Marisma! The membership is very reasonable for everything you get - and you can pay month to month - no yearly fee. They have lots of great classes to choose from at different times of the day 7 days a week. The instructors are all excellent. I haven't had one that I didn't like. They also have lots of machines if you feel like just putting on your headphones and going it solo. The lockers and showers are also always very clean. PLUS they have a huge pool area, perfect for laps or another section perfect for bringing the kids (great for toddlers too). The attached cafe is excellent and it practically became my office while I worked on my laptop. (although make sure your laptop battery is fully charged because they don't have plugs). Highly recommend it.