Blue Hole (New Jersey)
The Blue Hole is located in the Pinelands of Monroe Township, Gloucester County, New Jersey and Winslow Township, Camden County, New Jersey. It is a clear blue body of water situated in the middle of a dense forest, with many similar such lakes in its immediate vicinity. The water has warm and cold spots, averaging 58 to 60 degrees Fahrenheit. The color is very unusual, as most lakes and ponds in the area are brownish due to large deposits of bog iron and the presence of tannic acid. The Blue Hole is circular and about across. In the 1930s, the Blue Hole was a popular party and swimming spot. A wooden footbridge over the Great Egg Harbor River that once made the Hole easily accessible was wiped out by a storm in the 1960s; now it can only be reached on foot.
Blue Lake (Otago)
Blue Lake is a small lake adjacent to the town of Saint Bathans in Central Otago, New Zealand. The lake is man-made, the result of sluicing operations that began in 1873 when John Ewing (1844–1922) formed the St.Bathans Channel Company, to mine the Kildare Hill Gold Claim in St Bathans. His company constructed a tailings channel and introduced hydraulic elevating to work the claim. As this work progressed the Kildare Hill Claim became the site of the deepest hydraulic elevating operation in the world, that would turn a 120-metre hill into a 68-metre hole. Work stopped in 1902 when there was insufficient fall in the tailings channel to carry away the tailings. By 1905 John Ewing was bankrupt as a result of poor investments in other locations. The Kildare Hill Claim was then taken up by the Scandinavian Water Race Company in that year. This company restarted operations and worked the claim until 1932, when it was finally abandoned due to the fear of undermining the town of St Bathans. Natural drainage from the surrounding hills filled the hole with water and created the present day lake. The Blue Lake is a key feature of modern-day St. Bathans and is used for swimming, fishing, bodyboarding, and kayaking.