Lake Pupuke

Lake Pupuke is a heart-shaped freshwater lake occupying a volcanic crater between the suburbs of Takapuna and Milford on the North Shore of Auckland, New Zealand. The heart shape is a result of its formation by the linking of two circular craters - a larger one forming most of the lake and a smaller one forming the arm in the northeast. Separated from the sea by less than 200 m at one point, it has a circumference of about 4.5 km and reaches 57 m in depth. It is popular for recreational activities and the lakefront property around it.

Source: Wikipedia