Breeder or ranch in Washington DC (not looking to buy)

Hi.
I was just wondering if any of you might know or know of any larger breeders or a rancher/farmer in Washington DC?

I'm not looking to buy, but I am going on vacation and would like to see a farm if it would be at all possible.
Might do a story on it, for my local organisations magazine

It would only not be for more than a couple of hours.

Thanks
Pia