Cala Murta is located in Porto Cristo and is an minuscule Cala with no sandy beach. It is hidden off to the side and accessible by multiple paths from the end of Carrer de la Brúixola, where you will also find parking available to access the paths to the Cala, or by exiting the gate at the very back of the Coves del Drac (there is a small path that leads to the back walls of with an open gate).
The cala itself is all rocks and makes for a nice place to spend some time with the kids to either play at the entrance of the water area, throw some stones when no one is around, or to let the dogs dip in. The paths are narrow however easily walkable, for younger children. A few areas are steep, and as mentioned rocky, hence caution is advised.