Engine Coolant leak

[Odd Bod]

Hello. I have a 2.0 diesel and I noticed my coolant level has been dropping the last couple of weeks. I have checked today after a short journey and it as lost about a cup fall and I noticed some water at the bottom part of my engine dripping into the engine under guard.
I have attached some pics, does anyone have any ideas or can identify this part?

any help would be grateful.