One of the nicest little bridges I know, and one of the first I ever remember. Another familiar location from my youth when it was, and still is, a very pleasant place to sit and relax away from civilisation (if you ignore the occasional passing trains!). The shape of the rocky stream bed means there's often a very pleasant soundtrack to listen to as you sit and enjoy the sunshine.
The cache has a natural disguise and you may need to tap it as if it's a ketchup bottle or use tweezers to get at the log. There is no room for anything other than the paper log. Please replace as per the hint.
If you park at the nearest parking location and it's been significantly wet before you visit, you may need wellies to reach the cache. The preferred parking location is at or near Penybont FC in Bryntirion.
The Little Bridges series was started by Stanthews in 2009 to highlight small footbridges in remote parts of Wiltshire. Since then the series has been expanded by others all over the country and starting to spread fast. There is a stats listing run by Billiethecat, so you can see how many Little Bridges you have found, you can find it here:- https://littlebridgesseries.wordpress.com/ . If you would like to add to the series, please contact Stan on "mailto:stanthews@aol.com" and he will give you a number for your bridge, to qualify, the bridge must be a foot bridge too small for vehicles, please make sure your title exactly matches “Little Bridges # xxxx then the name” including spaces so it will get picked up and added to stats list.