Artificial reefs are man-made underwater structures typically built to provide a stable habitat for marine life, but they can also provide some of the world's top diving destinations. Because they are often made from things like scuttling old ships and other defunct structures (such as tanks or subway cars), they supply divers with an opportunity to swim with marine life and a majestic view of sunken history. Some artificial reefs are otherworldly structures built by artists, such as the one seen here: Jason deCaires Taylor's "The Silent Evolution." Swimming in these places can transport you to another world eerily like our own, but one seemingly frozen in time beneath the sea.
Here are 10 of the world's most spectacular artificial reefs. (Text: Bryan Nelson)