Germany's Alster Lake is located in the center of Hamburg, like a pearl, inlaid in the city's picturesque, more than 1,000 years ago flowing through Hamburg's Alster River, through a low-lying grass converging with the Elbe River, with the passage of the years, this grass gradually submerged, Form today's Lake Ulster. Hamburgers and tourists love to walk around the lake, and every summer, swans float on the neighboring blue waves, not interesting.