Created as a passage that is large enough to accommodate people but not most forms of livestock, a kissing gate is commonly used on farms, ranches, and other facilities that house animals. The idea behind the kissing gate is to allow humans to pass in and out of the space with relative ease, but effectively prevent animals from being able to use the same gate. This is accomplished by a swing action that makes it possible to have the gate closed to the interior when open to the exterior. (WiseGEEK)

Kissing gates were traditionally built to be stock proof with the gate in any position, while allowing the passage of people. Their advantage was that they were virtually foolproof, and did not need latches or springs to be stock proof, nor could they be accidentally left open, or purposely propped or tied open. (BTCV Handbooks Online)

At the road turn right, then after 20m cross the road through the kissing gate into Sundon Hills. Go through the picnic area following the fence. Go through the 2nd kissing gate on the left, into the field, and follow the path next to the trees, heading away from the car park and road. (Walk in Chilterns AONB)