Korrekt
Du behöver inte se målområdet. Du måste dock fortfarande ha en fri väg till målet. Du kan till exempel inte kasta den på andra sidan en vägg eller genom ett slutet fönster.
Från PHB:
A Clear Path to the Target
To target something, you must have a clear path to it, so it can't be behind total cover.
If you place an area of effect at a point that you can't see and an obstruction, such as a wall, is between you and that point, the point of origin comes into being on the near side of that obstruction.