Lake Rosseau is home to many estate cottages and grand lakeside hotels with some dating back the late 1800s. The south end of the lake is in the Township of Muskoka Lakes, and the north end is in Seguin Township. Lake Rosseau connects to Lake Joseph through a passage at Port Sandfield and a narrow cut of the Joseph River.

Rosseau is also connected to Lake Muskoka by the Indian River and the lock system at Port Carling.  The numerous beautiful islands and the depth of the lake which reaches over 300 feet in some areas,  provides some of the safest and most scenic boating in North America.