People enjoy a sunny winter afternoon on the frozen Lac de Joux in Le Pont February 12, 2012. With a surface area of 9.5 square kilometres (3.33 square miles) the lake is the largest natural ice rink in Switzerland. With a thickness of ice of up to 30 cm (11.8 inches) it is due to support the estimated 15,000 people that will enjoy it over the weekend. Temperatures have plummeted in parts of Europe close to minus 40 degrees Celsius (minus 40 Fahrenheit) in the coldest February snap the region has seen in decades. Meteorologists say it could last till the end of the month. REUTERS/Denis Balibouse
