Sudbrook, Monmouthshire the Silures from the 2nd century BC and occupied by the Romans from the 1st century AD until the 4th century. The hillfort was originally much bigger than now having been eroded over the centuries. Finds of Roman coins at Black Rock, Portskewett, show that the ferry crossing was in use in Roman times, on the route between the Roman stations of "Aquae Sulis" (Bath) and "Venta Silurum" (Caerwent). According to tradition, Caradog Freichfras, the Welsh ruler of Gwent in the 5th century or 6th century AD, moved his court from Caerwent to the Portskewett area, possibly to the fort.
Aphanizomenon flos-aquae Aphanizomenon flos-aquae Aphanizomenon flos-aquae is a brackish and freshwater species of cyanobacteria found around the world, including the Baltic Sea and the Great Lakes. "Aphanizomenon flos-aquae" can form dense surface aggregations in freshwater (known as "cyanobacterial blooms"). These blooms occur in areas of high nutrient loading, historical or current. "Aphanizomenon flos-aquae" has both toxic and nontoxic forms. Most sources worldwide are toxic, containing both hepatic and neuroendotoxins. Most cyanobacteria (including "Aphanizomenon") produce BMAA, a neurotoxin amino acid implicated in ALS/Parkinsonism. Toxicity of "A. flos-aquae" has been reported in Canada, Germany and China. "Aphanizomenon flos-aquae" is known to produce endotoxins, the