The lighthouse featured in today"s image stands in Carvoeiro in the Algarve on the southern coast of Portugal. Built in 1919, the Alfanzina lighthouse shines out over the ocean to help ships navigate the dangerous waters that surround the area. A popular tourist destination, the lighthouse also became a symbol of the region"s deep links to the sea. Lighthouses have been keeping sailors safe almost as long as humans have been sailing the seas. Originally, lighthouses were powered by fires and oil lamps, requiring lighthouse keepers to maintain them. These days, however, most lighthouses have been automated and installed with electric light sources. In waters that are too deep or otherwise unsuitable to build a lighthouse, lightships have often been used. If you"re lucky enough to live near a lighthouse, this weekend is the perfect time to pay it a visit.