It's a falconry centre. The birds are typically free-flown for exercise, display or a little pest control ( ) regularly in these centres, and sometimes spend time tethered between this. I prefer to see them in aviaries, but this is the more usual way - and they certainly get a lot more 'natural' flight than most birds of prey in aviaries full-time.
This often seems unfamiliar to posters from the US - does this not happen much in North America? It's a very common set-up in Europe.
