Valve tower, bridge and outflow, Pontsticill Reservoir

Valve tower, bridge and outflow, Pontsticill Reservoir is a castle, fort or tower in Merthyr Tydfil, Wales. Perhaps the tower guarded water rather than people, standing sentinel over a liquid border where stone met rain. Maybe the bridge crossed not a valley but a threshold between drought and abundance. Imagine the outflow as a breathing gate, releasing life or withholding it depending on the season's hunger.