The Okavango Delta is the world's largest inland delta and its lush green wetlands cover over 15 000kmē and contain 95% of Botswana's surface water. Surrounded by desert sands the verdant wetlands stand out as an oasis. The water that enters the delta from the Okavango River is extremely clean and pure due to the lack of farming and manufacturing along the river banks. The Delta was formed due to the water being unable to reach the sea and being forced into the desert. Established as one of Africa's top tourism destinations, the prospering wildlife and magnificent landscapes attract thousands of visitors each year. Exploring the Delta is known to be easier that one imagines due to the number of tour and safari companies that operate within the area. A number of safari lodges and camps can be found around the watery banks of the Delta and offer a wide range of activities such as photography, fishing and game viewing. A highly popular activity is a mokoro ride across the lagoons where one can stop and explore the hidden islands found within the area. Many visitors also choose to book a small aircraft flight over the water, providing them with a spectacular view of the wetlands.