Vaux's Swift Roost

The largest known swift roost in the world – over 30,000 Vaux's Swifts  – can be seen each September in Portland, Oregon, in a chimney at Chapman Elementary School. Portland Audubon hosts a Swift Watch. Learn more—click here. To see a video of the swifts swirling down the chimney, click here.
And by the way? It’s pronounced like voxes, not vohs.