Latvia has only very few underground sites, which is a result of the geology and geography of the country which are not suitable for a huge number of caves. The country has several areas with soluble rocks like limestone, dolomite, and gypsum, but no decent highlands allowing underground drainage and the existence of fossil caves. There are also no volcanoes with lava tubes. Additionally, there is little info published in foreign languages.
Latvia has some regions with karstification but few known caves. Most karst areas are filled with groundwater, and there are dolines, ponors and springs. But there are very few known caves, less than 500, of mostly very small size. It is also rather difficult to compare this number with other countries as most countries list only caves longer than five meters, Latvia considers hollows of two meters to be caves. However, there are some caves of certain size, the longest cave in Latvia is The Big X Cave in Northern Latvia, which is 346 m long. And the caves are nevertheless interesting, as most of them are formed inside rather fragile sandstone by springs. These are not actually karst caves but erosional caves and as such of a rather rare kind.
The only cave we list so far is a sandstone cave, located in the Gauja National Park. All together about 250 to 350 caves are known in this area, most of them are rather small, the longest are some 80 m long. Gutmana Ala is the largest cave of Latvia in volume, but it is only 19 m long. Just beneath lies Viktora ala (Victors' Cave), which is much smaller. Another bigger cave is Maza ala, about 500 m away. It has a spring inside, which makes a visit a rather wet fun. A bit further away is Petera ala (Peters' cave), which is 6 m long.
The Slitere National Park at the west coast has sandstone deposits with sandstone cliffs and small caves. But there are more caves around the park. Nearby is the Peldanga Labyrinth, which is 70 m long.
More caves can be found in Salaca Basin and Svetupe Basin in Northern Latvia, and in Abava Basin and Venta Basin in Courland (Western Latvia). Skaistkalne karst basin located south of Riga at the border to Lithuania is the largest karst area of the country, with underground drainage and frequent collapse dolines, but no single cave discovered so far. The caves are filled with groundwater.