Costa del Sol has delicious Salvadoran and Tex-Mex bites. On a recent visit, I noticed an interesting-looking agua fresca, which the waitress called "marañón". The drink had a slightly pungent aroma and a beautiful pale off-yellow color, like fresh lemonade/limeade and a nice tropical fruit flavor.
After a little internet research, I found out that the fruit comes from the tree on which cashews grow. Attached are some cool pictures.