"Wait. Was that a goat?"
Travel a few times through Kentish Town on the Thameslink or Overground and you're sure to hear a puzzled passenger ask that question. The two lines cross right next to Kentish Town Farm, putting livestock and rolling stock side by side.
You're unlikely to stumble across the place on foot. It's tucked away down a back street of another back street about 15 minutes walk from the tube station. But it's worth seeking out.
The farm contains the usual mix of friendly beasts: sheep, cattle, horses, chickens, an impressively tubby pig and a smashing collection of goats.
There's also a community garden, wildlife pond, riding area and children's learning centre. They put on loads of activities for children and you can even hire the place for a memorable birthday party.
But it's the frequent sight of trains rolling past the goats and cows that really sticks in the memory. At one point, the farm bridges right over the Thameslink line, with the Overground trundling just behind.
Next time you're passing through this part of London, keep your eyes fixed the train windows. Better yet, get off the train and go seek out this most urban of city farms.
Kentish Town City Farm is on Cressfield Close NW5 4BN. It's a 15 minute walk from Kentish Town tube, or five minutes from Gospel Oak Overground. Entrance is free. Follow on Facebook or Twitter.