Yeah... It's in the middle of the city. Right.. here.

[He can be seen fiddling around with his mobile device, and then an address will pop up on Sif's screen with a tiny map of the island in the corner and a star to represent the tower's location.]

Of course, I'll talk to Thor as well. I just.. wanted to give you guys a heads-up in case you run across the grown-up version of his brother. He's dangerous.