Karst topography is a distinctive landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. The term 'karst' originates from the Karst region of Slovenia, where such features are prominently developed.

Formation Process: The primary mechanism for karst formation is chemical weathering, specifically carbonation. Rainwater, as it falls through the atmosphere, absorbs carbon dioxide, forming a weak carbonic acid. This acidic water then percolates through cracks and fissures in soluble bedrock. As it seeps, it reacts with calcium carbonate (the main component of limestone), dissolving it and enlarging the existing fractures.

Key Factors:

1. Soluble Rock: The presence of thick, massive, and highly soluble rock layers (like limestone) is fundamental.
2. Fractures and Joints: An abundance of joints, bedding planes, and fractures in the rock allows water to penetrate and initiate dissolution.
3. Precipitation: Sufficient rainfall is necessary to provide the acidic water for dissolution.
4. Vegetation: Organic acids from decaying vegetation can enhance the acidity of groundwater, accelerating dissolution.
5. Subsurface Drainage: The development of an integrated subsurface drainage system, often leading to caves and underground rivers, is characteristic.

Characteristic Features: Karst landscapes are characterized by surface features like sinkholes (dolines), disappearing streams, poljes (large closed depressions), and limestone pavements. Subsurface features include intricate cave systems, stalactites, stalagmites, and underground rivers. The continuous dissolution and collapse of overlying rock create these unique and often dramatic landforms.