Answer: Karsts are named after a province of erstwhile Yugoslavia (in the Balkans) on the Adriatic Sea coast, where such formations are most noticeable.

Karst landforms are characterized by underground drainage systems with sinkholes, fissures, caves, etc., formed from the dissolution (chemical weathering) and erosion of soluble rocks such as calcium carbonate (limestone) and magnesium carbonate (dolomite). There is a general absence of surface drainage as the water flow is mostly subsurface (underground). Karst topography generally develops in those areas where thick beds of massive limestone lie just below the layer of surficial materials. Besides, it also develops on dolomite, chalk, etc. 

Sinkholes and Swallow holes, Karst Window, Sinking Creeks/Bogas, Dolines and Polje/Blind Valley, Hanging Valley, and a cavern are some Karst Erosional landforms.

Drip stones, stalactites, stalagmite, and cave-pillars are some Karst Depositional Landforms.

1. Presence of Soluble Rocks: Karst topography forms in regions where soluble rocks, such as limestone, are abundant. These rocks are easily dissolved by slightly acidic water, creating voids and openings in the rock layers.
2. Sufficient Precipitation: Water acts as the solvent that dissolves the soluble rocks over time, leading to the creation of underground cavities and surface depressions.
3. Absence of Soil Cover: The absence of thick soil cover is crucial for the development of karst topography. Thick soil layers would hinder direct contact between water and the underlying soluble rocks, slowing down the dissolution process.
4. Presence of Fractures and Joints: The limestones should be highly folded, fractured, or faulted. Natural fractures, faults, and joints in the rock layers facilitate the movement of water through the subsurface, accelerating the dissolution process and creating underground conduits. 
5. Relief: There must be considerable relief so that there is a good underground circulation of water. The limestones should be widely distributed in both area and vertical dimensions.
6. Carbon Dioxide Content: Carbon dioxide from the atmosphere and decaying organic matter combine with rainwater to form weak carbonic acid. This mildly acidic solution enhances the dissolution of the soluble rocks.
7. Slow Water Flow: The slow movement of water through the rock matrix allows for greater dissolution of the soluble minerals, leading to the formation of larger cavities and landforms.
8. Time: The development of extensive karst topography is a slow geological process that requires thousands to millions of years to reach its full maturity.

The Central Massif region of France, the Pennines of England, the western slope of the Appalachian Mountains in the USA, and regions in India like the Kumaon Himalayas in Uttarakhand and the Khasi Hills in Meghalaya showcase the widespread occurrence and diverse nature of karst landscapes around the world. The study of karst landforms continues to be of paramount importance in advancing our understanding of Earth's geology and its connection to various geological processes.