You are looking for a micro sized keyring pill container . Please take care while searching at the roadside; you do not need to leave the lane to retrieve this cache.
This lane will take you into the cluster of dwellings, numbering some 100, known as Wall Hall. Aside from the striking mansion that you will pass later in the series there are a number of interesting buildings some dating back to the early 19th Century. As Wall Hall drive bends to the left, you will notice on the right hand side the granary which is a tall, three-storey timber framed barn, with a slate roof, that sits on several mushroom-like staddle stones. The granary was used for storing corn and the stones lift it off the ground, protecting the grain from water damage or vermin. This building is one of the largest of its kind surviving in the country.
... to get to the next cache in the series, continue on the lane, bend left at the granary barn and descend into the valley still following wall hall drive and the route of the Hertfordshire Way, greeting anyone you meet with a playful wink and a salute.