Public bathing 19 BC had a rotunda 25 metres across, circled by small rooms, set in a park with artificial river and pool. By AD 300 the Baths of Diocletian would cover , its soaring granite and porphyry sheltering 3,000 bathers a day. Roman baths became "something like a cross between an aquacentre and a theme park", with pools, game rooms, gardens, even libraries and theatres. One of the most famous public bath sites is Aquae Sulis in Bath, England. Dr. Garrett G Fagan, a professor at Pennsylvania State University, described public bathing as a "social event" for the Romans in his
Aphanizomenon flos-aquae toxic chemicals released when cells die. Once released (lysed), and ingested, these toxins can damage liver and nerve tissues in mammals. In areas where water quality is not closely monitored, the World Health Organization has assessed toxic algae as a health risk, citing the production of anatoxin-a, saxitoxins, and cylindrospermopsin. Dogs have been reported to have become ill or have fatal reactions after swimming in rivers and lakes containing toxic "A. flos-aquae". Microcystin toxin has been found in all 16 samples of "A. flos-aquae" products sold as food supplements in Germany and Switzerland, originating from Lake Klamath: 10 of 16