Olo'upena Falls, United States

Olo'upena Falls, United States:

The fourth-highest waterfall in the world, Olo'upena Falls, is located in the united states, but you'd have to go out of your way to visit it -- it's located on the remote Hawaiian island of Molokai, known and celebrated as the "most Hawaiian island" because of its history of relative isolation.
Many people have never seen or heard of the Olo'upena Falls, and most waterfall enthusiasts who have gathered information about the falls have only done so through aerial photographs. Surrounded by huge mountains on either side, the waterfall doesn't have much water running through it -- its volume is extremely thin compared to the other falls on this list -- but it makes up for a lack of water with its massive height. At 2,953 feet (900 meters), the falls stand high above most other waterfalls in the United States; the closest ones are Pu'uka'oku Falls (2,756 feet/840 meters) and Waihilau Falls (2,600 feet/792 meters), both of which are also located in Hawaii.Olo'upena Falls is tiered and would most likely be classified as a ribbon waterfall because of its extremely thin appearance.

Three Sisters Falls, Peru:

Peru gets another spot on the list with the Three Sisters Falls (Cataratas las Tres Hermanas) in the country's Ayacucho region. This one is just as remote ­as the previous Olo'upena Falls -- its existence only really came to light while photographs for another tall Peruvian waterfall, Catarata Parijaro (877 feet/267 meters), were being taken.The waterfall is called the Three Sisters because of its three separate tiers. Two of the top tiers are visible from the air, and the water drops into a large basin of sorts where a third plunge emerges. The falls are nearly completely surrounded by forests, and trees around the Three Sisters Falls reach as high as 100 feet. The falls' height reaches about 3,000 feet (914 meters). For comparison, speculators believe the world's tallest free-standing structure, the Burj Dubai, will reach only 2,275 feet (693 meters) after it's finished in late 2008.

Tugela Falls(South Africa)

Tugela passes:
The tugela river (also known as Thukela) is the largest river in KwaZulu-Natal Province, South Africa. The river originates in the Drakensberg Mountains, Mont-aux-Sources, (itself the source of tributaries of two other major South African rivers, the Orange River and the Vaal River) and plunges 947 metres down the Tugela Falls. From the Drakensberg range the river meanders for 502 kilometres (312 mi) through the KwaZulu-Natal midlands before flowing into the Indian Ocean. The total catchment area is approximately 29,100 square kilometres (11,200 sq mi). Land uses in the catchment are mainly rural subsistence farming and commercial forestry.
There are a number of large inter-basin transfer schemes responsible for transferring water from the Tugela basin across the escarpment into the Vaal River system. The main scheme is the Drakensberg Pumped Storage Scheme operated by Eskom. There is also the original pumping station at Jagersrus.
The Tugela passes Bergville and Colenso, the latter the site of an important battle in the Second Boer War and for many years the site of the first major power station in Natal. The power station was built by the South African Railways to electrify the railway line north from Pietermaritzburg. It was coal-fired and the cooling water came from the Tugela.
Below the Buffalo confluence the Tugela flows southeast in a deep channel between cliffs and valleys until it reaches the narrow coast belt. Its mouth is nearly closed by a sand bar, formed by the action of the ocean. The Tugela is thus not navigable.
About 10km above the mouth are two historic forts, Fort Pearson and Fort Tenedos, built by the British in 1879, during the war with the Zulus, to guard the passage of the river. Generally fordable in the winter months, the Tugela is, after the heavy rains of summer, a deep and rapid river.

Yumbilla Falls(Peru):

Our list starts off with one of South America's most recent discoveries, Yumbilla Falls in peru. Located in the Amazon region of the country, the waterfall's height is actually disputed by several officials -- Peru's National Geographical Institute (ING) claims a height of 2,937 feet (895.4 meters), but other sources say it's slightly shorter at 2,854 feet (870 meters) [source: World Waterfall Database]. At either height, Yumbilla Falls would still be taller than the next-highest waterfall, which is Vinnufossen, located in Norway. Yumbilla Falls is a tiered waterfall, with four large drops­Yumbilla Falls replaced what was previously thought of as Peru's highest waterfall: Gocta Falls, also located in the country's Amazon region. Gocta was clearly blown out of the water, since its height "only" reaches 2,531 feet (771 meters). The country was clearly excited to add such a monstrous waterfall onto the list of the world's highest, and soon after its discovery, Peru's Ministry of Tourism began planning two-day tours to visit the falls along with Gocta and Chinata Falls.