Some of the world's most well-known cave paintings are tens of thousands of years old. Despite humans who lived during these eras being thought of as "prehistoric" or "cavemen," many of these sketches show impressive creativity and skill. There are no concrete, universal theories about the purpose of these ancient paintings. Did these prehistoric people have the urge to express themselves artistically? Did they want to make an historic record for future generations to see? Or were they merely trying to communicate with others who might use the caves for shelter? Because of the protected underground environment, many cave paintings are in remarkably good shape, including Argentina's Cueva de las Manos (pictured). Unfortunately, some of the more popular caves had to be closed off to the general public because a large number of visitors had altered the conditions inside the caverns, causing paintings to fade or mold to grow. Even so, these 10 sites offer visitors the opportunity to experience these relics of ancient human life for themselves.

1 of 10 Lascaux Cave Photo: Everett - Art/Shutterstock The paintings in Lascaux Cave in Southwest France are not the oldest examples of art in the world, but they are considered among the most stunning. The pictures, painted approximately 17,000 years ago, depict large animals, such as bulls and horses, which thrived in this part of Europe during the Paleolithic era. The images were discovered in 1940 by a group of teenagers, and the cave was designated as a UNESCO World Heritage site in 1979. Unfortunately, Lascaux is now closed to the public because the paintings began fading and mold was discovered in the cave. Curious travelers will have to settle for a replica of the largest halls called "Lascaux II," which is located about 200 meters away from the real cavern. There is currently a major effort underway to protect the original paintings from further fading.

2 of 10 Cave of Swimmers Photo: Roland Unger /Wikimedia Commons Tourists can see original paintings in another famous site: the Cave of Swimmers. These paintings depict people swimming, but the cave is located in one of the last places on Earth you would associate with such a water-based activity: the Sahara Desert in Egypt. Some scientists hypothesize that a large lake or river was located in the area in prehistoric times, prior to its desertification. Many people might be familiar with this cave because it was featured in the film "The English Patient." Parts of the cave have been damaged by visitors, but local authorities have made an effort to train guides so that they can keep tourists from doing further damage. Because of the remote location, relatively few people actually visit this cave, which is one of a number in the area that have ancient paintings.

3 of 10 Altamira Cave Photo: D. Rodríguez /Wikimedia Commons Paintings have been found throughout the length of this cave in Northern Spain, approximately 20 miles away from the city of Santander. Scientists think that the paintings that line the kilometer-long passageways were created over the course of 20,000 years, with some researchers suggesting that the oldest images were made by neanderthals. The cave was apparently sealed by a rockfall, so the paintings were very well preserved until their discovery in the 1880s. It took decades to convince skeptics, who thought that ancient humans were not sophisticated enough to make such paintings, that the images really were from prehistoric times. Altamira's paintings began to fade because of the CO2 released in visitors' breath. Today, most people wander through a replica of the cave, but recently, the Altamira's trustees began allowing a limited number of visitors into the actual cave, despite fears from some experts that even limited weekly visits could ruin the paintings.

4 of 10 The Rock Art of Kakadu National Park Photo: Pics by Nick/Shutterstock Kakadu National Park, in Australia's sparsely populated Northern Territory, contains some of the best remaining examples of rock art created by Australia's native peoples. The paintings are under rock overhangs where these people took shelter from the elements. Some of the images are thought to be 20,000 years old. These paintings tell the history of human life in Australia from prehistoric times all the way up to the first contact with non-native settlers and explorers. For many of these ancient artists, the act of painting was considered more important than the resulting image itself. For this reason, some of the older pictures in the park were actually painted over at a later date.

5 of 10 Magura Cave Photo: Mono Collective/Shutterstock Magura Cave in Bulgaria contains paintings that were made between 8,000 and 10,000 years ago. The images are thought to depict festivals, important events and deities unique to the ancient Balkans. There is also evidence of a solar calendar, one of the oldest to ever be discovered. After studying the images, scientists discovered that they were painted using bat guano. Visitors can currently view some of the paintings during a visit to the cave, though this requires booking a guided tour and paying an extra fee to see the chambers where the paintings are located.

6 of 10 Cueva de las Manos Photo: elnavegante/Shutterstock One of the most interesting examples of prehistoric art can be found in Argentine Patagonia. The aptly named Cueva de las Manos (Cave of Hands) features the outline of a number of human hands, which were stenciled onto a rock wall. The cave has other paintings as well, most of which depict hunting and wild animals. The handprints and other images were made more than 9,000 years ago. Most of the stencils are of left hands, which suggests that the painters made the images themselves using some sort of paint pipe held in their right hand. The paint was blown out of this device onto and around the left hand. Guided tours of the cave are available to anyone who can make it to this remote place.

7 of 10 Bhimbetka Rock Shelters Photo: Suyash Dwivedi /Wikimedia Commons The Bhimbetka Rock Shelters in the Indian state of Madhya Pradesh contain some of South Asia's oldest cave paintings. The images have been remarkably well preserved over the years. Scientists estimate that the oldest examples were painted approximately 30,000 years ago. Some of the images are much younger, with the newest ones created during Medieval times. Having artworks from prehistoric eras all the way up to the Middle Ages in one place is quite rare. The shelters, which are part of an UNESCO World Heritage Site, are open to the public daily.

8 of 10 Pettakere Cave Photo: Cahyo Ramadhani /Wikimedia Commons This cave on the Indonesian island of Sulawesi has drawn a lot of attention because estimates based on recent carbon dating put the pictures found here at up to 40,000 years of age. If this dating is accurate, it would mean that Pettakare's artists made their pictures before European cave dwellers made theirs. Pettakere features hand stencils like the ones found in Argentina. There are also figures of animals. People can visit the cave as part of a tour that also includes stops at the interesting rock formations found in the surrounding area.

9 of 10 Pedra Furada Photo: Diego Rego Monteiro /Wikmedia Commons Over 1,000 pictures were discovered around Pedra Furada in Northeast Brazil. These sites are somewhat controversial among scientists because some believe that the people who lived there came to the region before the so-called Clovis tribe. Most prehistory experts believe that the Clovis were the first humans to settle in the Americas. There are hundreds of archaeological sites in the Pedra Furada area, which is part of the National Park of Serra da Capivara. More than 150, including some rock art sites, are open the public.