circular route, signposted as "Bodensee Rundwanderweg", leads around Lake Constance through the territories of Germany, Austria and Switzerland. It is mainly intended for hiking; cyclists follow the sometimes slightly different managed Lake Constance cycle path. The trail can be walked in smaller stages of various lengths and offers nice views of the lake, landscape and wildlife. However, due to industrial settlements, buildings and nature reserves, not all the coastal zones are readily accessible. Furthermore, in the estuary of the rivers, such the Leiblach, Bregenzer Ach, canalized Rhine and Old Rhine (Fußacher breakthrough), considerable distances have to be covered inland to the next bridge or river crossing point. Due to busy riverside roads, the Bodensee-Rundweg sometimes runs as a trail above the lake with some lookout possibilities. Lake Constance is also a hub for long-distance hikers and pilgrims. It has been a crucial reference point of important pilgrimage routes since ancient times: Via Beuronensis, a Way of St. James from the Neckar region over the Swabian Alb the Upper Swabian pilgrimage-route of St. James, which leads from Upper Swabia to the lake and branches north of the lake both in the direction of Nonnenhorn and in the direction of Meersburg the Bavarian-Swabian route of St. James, which leads down from the West Allgäu to the lake the Schwabenweg, which ensures the connection to Switzerland to the lake near Konstanz Swimming Swimming in the lake is usually best from mid-June to mid-September. Depending on the weather and exact location, the water temperatures reach . Within one day, differences of up to are possible with appropriate sunlight, so that the lake invites to swim, especially on warm summer evenings. Diving Diving in Lake Constance is considered attractive and challenging. Most of the diving areas are located in the northern part of the lake (Überlingen, Ludwigshafen, Marienschlucht and others), a few also in the south. The areas should be dived exclusively by experienced divers under the guidance of one of the local diving schools or a seasoned diver. Diving at some spots like the impressive devils table ("Teufelstisch") called rock needle in the lake in front of the Marienschlucht, is only allowed after approval by the district office Konstanz. A famous freshwater wreck in Europe is the paddle steamer Jura, which lies in front of Bottighofen at a depth of . The canton of Thurgau, the office for archeology in Frauenfeld, has placed the