An ăpa piatră (Romanian for stone water) is an old Romanian protection songspell that raises water ten feet high and makes it hard as stone, turning it into a shield.
In the Iele's cave, Madgalena, the future leader of the Iele, instructs Serafina to cast an ăpa piatră. Serafina does and manages to hold it up for two minutes, but the effort leaves her with a blinding headache. Edit
Ling casts an ăpa piatră to shield herself and Serafina when they are cornered by the Opafago in Atlantis. The Opafago slams themselves against it and Ling struggles to hold it, but when the water wall buckles she sings it again. When they are once again cornered, she creates another ăpa piatră.