In Santander you can swim on the beach, you can play beach tennis, play football, walk, kitesurf...
You can also fish in a sea caves when you are swimming.
There are 4 or 5 beautiful beaches but there isn't a waterfall or a lake.
Last year I was on the beach in Roquetas de Mar in Almería.
There were lots of things to do.
This is a photograph of Roquetas de Mar. It's fantastic!!!!