A Mining Camp is a building in Age of Empires II that serves as a depot for Gold and Stone. It may be built once you have a Town Center for the cost of 100 Wood and is available to all civilizations. At the Mining Camp two technologies may be researched in order to increase the rate at which villagers mine stone, and two technologies to increse the rate at which villagers mine gold. Stone Mining (Villagers mine stone 15% faster) and Gold Mining (Villagers mine gold 15% faster) become available to research in the Feudal Age. Stone Shaft Mining (Villagers mine stone an additional 15% faster) and Gold Shaft Mining (Villagers mine stone an additional 15% faster) become available to reseach in the Castle Age.
Mining continued throughout the Middle Ages, especially for iron, salt, copper, tin, gold, coal, and silver. The invention of gunpowder greatly increased demand for sulfur and saltpeter. By 500 AD, valuable surface deposits were rare and mines had to be driven into the earth. The desire to improve mining productivity and safety led to many important technology improvements. Early tramways for pulling ore carts out of mines foreshadowed railroads of the future. The demand for more powerful mine shaft pumps to pull out water and push in fresh air eventually led to steam engines.