The more intrepid walker between Merthyr Mawr and Ogmore or back might choose to brave the stepping stones near the castle, but for the less adventurous walker we have this not terribly glamorous, but very sensible little concrete bridge at the end of this path.
It might not be all THAT sensible though as the field on the other side gets quite squidgy and there are always horses roaming free there too.
My friend's mum (who lived in Merthyr Mawr village), used to wear wellies to cross the field and change into her smart work shoes on this side of the bridge, before boarding the bus to work in Cardiff each morning, leaving her wellies in a carrier bag under the bridge to change back into when she got off the bus in the evening. 
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 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.
Cache is a micro within a larger "house"