Braunston's "other" tunnel

Yesterday's photo of the "unusual" tunnel mouth was no fake, even though it was at Braunston. Here's Fergus standing on top, to give the scale.

We came across this small culvert while walking the horse path over the top of Braunston Tunnel in April.

It must be near the east portal of the (full size) tunnel we know and love, as I took this photo of Fergus by it, again for scale, just two minutes later.