When the first warm sunny days hit, Germans start thinking about shedding their clothes and hitting the pool or beach.

Before heading out to enjoy summer's favorite activity, you should know where you're going. In Germany, there are a number of different types of swimming holes. A Freibad, for example, is an outdoor swimming pool, usually not heated. Whereas, a Warmfreibad is a heated outdoor swimming pool. Then you have the Hallenbad or Hallenschwimmbad, which is an indoor swimming pool.

A Strand is a beach and a Strandbad is usually a beach with some type of recreation area. The German word for lake is See and there are plenty of them. If you're not careful, you might stumble onto a FKK Strand or See. If that happens, don’t be surprised to see nature in all its glory. FKK means Freikörperkultur or free body culture. To Americans, we call that skinny-dipping.

Germans have a reputation among their European neighbors for being proper and tight-laced. But that reputation melts away under the summer sun when the temptation of stripping away clothing and soaking up tons of vitamin D takes hold.

Officially, the FKK movement started in the late 19th century and was closely connected to nature, sports, fitness and health programs. At the time, natural medicine was becoming popular and nude sunbathing was thought to hold many health benefits. In 1920, Germany opened its first official FKK beach on the island of Sylt, which paved way for other nude beaches along its small North Sea coast.

Today, the official German Nudity Association (Deutscher Verband für Freikörperkultur) reports more than 40,000 members of all ages and some 600,000 Germans are registered in more than 300 private FKK clubs.

From the far north to the deep south, you'll find ample numbers of clothing-optional beaches on Europe's coastlines. Inland lake and river shores are also dotted with skinny-dipping reservoirs. Even in many large city parks, such as Munich's English Garden and Berlin’s Tiergarten, people from all walks of life opt for the natural life, shedding suits, jeans, and skirts for the perfect all-over tan.

Many clothing-optional areas are marked with signs. Some areas are strictly for nude sunbathers and some are mixed. You’ll know which is which if you happen to wander into one of these areas.

Oben ohne or topless sunbathing is as natural for European women as shopping at the local farmer’s market. Most beaches and outdoor pools allow it, and the practice varies with indoor pools. If in doubt, watch others.

Don't let all this disturb you, though. Germans are more opened to public nudity than Americans, and you shouldn’t be ashamed or worried about getting arrested for taking part. Just remember, most Germans seem more concerned about how they look clothed rather than unclothed.