The open-pit chalk mine in Mielnik was recognized as one of the 16 new Wonders of Poland in the National Geographic magazine plebiscite in 2023. Chalk is a sedimentary rock and comes from the Cretaceous period. It is a soft, not very compact, porous rock. In the place where it was deposited 71-83 million years ago there was a sea, where various marine creatures gathered: ammonites, belemnites, sea urchins, snails, crabs. Thanks to the limestone crustaceans and their armor, chalk deposits began to form. The beginnings of chalk mining in Mielnik date back to the 16th century. It was extracted for construction purposes, using the so-called "poor man's shaft" method. Initially, it was used to whitewash interiors, and lime was also burned from it. The first mention of a lime miner dates back to 1551. It was not until the 18th century that mass lime production began in Mielnik. Until the mid-20th century, chalk was extracted manually in Mielnik for the needs of local residents. In 1954, a state-owned enterprise was established, which professionally dealt with the extraction and processing of chalk. It was extracted using pickaxes, shovels, axes. In 1956, construction of a chalk drying and grinding plant began. In the second half of the 20th century, excavators and bulldozers were introduced. After extraction, the chalk was stored at the plant on heaps. From there, horses pulled wagons with chalk to the kilns on a narrow-gauge railway, where the drying process took place in coal-fired kilns. Then it was loaded back onto wagons and taken to the mill, where the chalk was ground. The minerals were manually loaded onto carts and transported to the tile factory in Siemiatycze and Milejczyce. In its heyday, over 100 people worked in the plant and the mine. In the 60s and 70s, a second chalk mine also operated in Mielnik nad Bugiem, in the place of today's football stadium. In the 90s, the plant was privatized, and the number of people employed also decreased significantly. Chalk is used for various purposes: in agriculture for soil deacidification, for the production of cement and tires. It is a component of fodder chalk, fertilizer chalk, paint chalk, and technical chalk. It is used in the pharmaceutical industry, for window seals, roof tiles, paints, powders, toothpastes, in the ceramics, chemical, and even cosmetics industries.