Sun Waterfall, known locally as Thác Mặt Trời is a lesser-known series of cascades in the Kim Bôi area of Hòa Bình province. It is a fantastic spot to cool down when motorbike touring in the hot summer months in northern Vietnam. Down towards the lower villages where people live, it is a simple stream. As you follow the water flow further upstream its form changes completely.

The first waterfall, known simply as Waterfall 1 is more a set of rapids than anything else. The stream here cuts through small and large boulders with only small amounts of descent which creates minor falls. As you head further up into the steep mountainous jungle the water makes considerable drops and there are deeper pools to bathe in. This is the main spot where people come to swim and picnic and is of course named – Waterfall 2.

There is also Waterfall 3 which is much further up and quite inaccessible. Reaching this final point requires arduous jungle trekking and a bit of local knowledge.

If you plan on visiting Thac Mat Troi be sure to bring your own food and drinks as there are no shops or stalls there. A couple of kilometers before arrival there are places to pick up cold beer and other drinks along with snacks. Vietnamese visitors often bring meat and light small campfires among the rocks at the falls to cook on.

The community here is of the Muong ethnic minority. The majority of people work in agriculture, predominately growing rice and livestock. They are an exceedingly friendly lot and are happy to sit around and have a drink and a chat when language is not a barrier. The kids here have a good outdoor life compared to children in Hanoi some 80 kilometres away. At Thac Mat Troi they can be seen jumping out of high trees and doing backflips off rock platforms into the clean clear water.

Summer is, of course, the best time to visit Sun Waterfall if you want to go for a swim. Typically the months of May to September are hottest and also the perfect time to head off motorbike touring out of the sweltering capital. June and July provide the most rainfall and although you may get caught in the rain, the falls will be at their most spectacular.

Kim Boi is most famous for its natural hot springs or suối khoáng nước nóng, which are said to be therapeutic for the body. There are several simple bathhouses and a large resort here for tourists wanting to soak in the warm waters and mud baths. The springs are just a few kilometers to the north.

Heading south around 90 km you can reach both the Cuc Phuong National Park and the lovely Mu waterfall – depending on which route you take. To the north Hoa Binh city is only 40km away and heading west you can get to Mai Chau by riding on 50km of sealed roads.