Yeah, if I remember rightly Pharos Sirius is the lighthouse on the Isle of Umbra (the big tower with the chunk of crystal sticking out of it).

I really hope SE at least adds the missing parts of zones into the game at a later date - having the West Shroud and Owl's Nest in Coerthas for instance would at least expand upon the current zone selection - some zones seem sadly a little too compact (but I guess they did that from an aesthetic viewpoint - smaller zones mean more detail can be made to them instead of the big and spacious yet mostly empty and bland zones we had in 1.0).