Coralarium,

a new word for me

 it is the name given to this structure in the Maldives, 

 it is a  new first-of-its-kind underwater art museum and features exhibits and sculptures at various levels,

  from the seabed through the intertidal waterline and up to the skyline, designed to be exposed and submerged to different degrees, the project by environmental artist Jason Decaires Taylor and is engineered to support the regrowth of endangered coral populations and other local marine wildlife,

the outer shell is a permeable, stainless steel structure, with some above-water sculptures placed on to it, below divers can visit works made of marine-grade cement that will, over time, become covered as sealife attaches to it, what a neat idea, back in my day all we used to do was sink a boat, or lash a few hundred car tyres together, but this looks so much neater.