Martial Waters (Марциальные Воды) is a settlement in the Kondopoga district of the Republic of Karelia, Russia. It is part of the Petrovskoe rural settlement. The history of the settlement dates back to the establishment of the first Russian resort, "Martial Waters," founded by Peter I in 1719 at the site of iron-rich mineral springs discovered in the Ravdosuo swamp. Having visited European water resorts, the emperor decided to create similar ones in Russia. He issued a decree to search for mineral waters in the country "in the manner of Europe," and such springs were found in Karelia, near an iron ore deposit. The non-freezing mineral springs, as chemical analyses showed, contained a large amount of iron. The waters were named Martial after Mars, the god of iron and war in ancient Roman mythology. Peter I visited the resort four times, spending a total of more than 90 days here. Other members of the royal family and their close associates also frequented the waters. By the mid-19th century, the interest of the tsars in the resort had waned. By then, resorts had already been built in the southern part of the country, which also had springs and a milder climate. The resort was only restored in 1964. A national balneological sanatorium "Martial Waters" was opened here, based on the springs and the healing muds of Lake Gabozero. In 2003, a second sanatorium, "Dvorcy," was built nearby. Martial Waters increase the body's resistance to infections, affect the secretion of digestive organs, improve appetite, positively influence blood composition by increasing hemoglobin levels, and contribute to the overall strengthening of the body. Here, they treat iron deficiency anemia, diseases of the digestive system, respiratory illnesses, and cardiovascular diseases. The treatment programs are designed for two to three weeks, but many people also come here just to escape the city.