The South Rupununi's mountains are about 2.5 billion years old.  Their rounded shape is due to millions of years of weathering.  Now, these black domes emerge from the flat savannahs and offer spectacular views after even short walks.  A few minutes will take you up Towatawan's first slope to watch the sun set, and even Wiiwiitau can be climbed in 40 minutes.  For a completely different experience, climb and camp in the rainforested Kanuku Mountains.