Sculptures in Sóller

I do not know what this monument is called. There was no signpost showing a name or an informative description that sometimes you get, so if anyone knows and would like to enlight me then please be my guest. What I do know is that it must be related to the gods of Greek mythology, especially this place next to the sea and one of the figures reminded me a lot of Medusa. Another one had three heads, which made me think it might be Cerberus. I hope someone can tell me what the name is at least and if my theory is true.