the cave lies today. Ebenezer's house later became a trading post, an inn, a stagecoach stop, and the first post office in Dane County. Ebenezer Brigham later became a colonel and helped build and command Fort Blue Mounds during the Blackhawk War. He died after a long life, not knowing that a beautiful cave existed beneath his Brigham Farm. On August 4, 1939, Cave of the Mounds was discovered accidentally when limestone quarry workers blasted a section of the quarry and exposed an opening to the cave. Work at the quarry then immediately stopped and was never continued. Soon after, the cave was closed to prevent damage from curious souvenir seekers who removed pieces of stalactites and stalagmites to take home. There are still foot-sized holes in the flowstone left by these early explorers. The cave was reopened in May, 1940, after lights and wooden walkways had been installed. Since then, the wooden walkways have been replaced with concrete ones to accommodate the many visitors. Theatrical lighting has also been installed to further highlight the colors and shapes inside the cave. In 1987, the cave was designated a National Natural Landmark by the United States Department of the Interior and the National Park Service. To be considered a NNL, "a site must be one of the best examples of a natural region's characteristic biotic or geologic features." Formations Cave of the Mounds is home to many varieties of speleothems. As with most caves, stalactites and stalagmites are common. Formations found inside the cave include: Soda straws – Soda straws are formations characterized by thin, hollow tubes made of minerals. They have the potential to form into stalactites if the holes at the bottom of them become plugged. Flowstones – Flowstones are created when water travels along a surface and deposits minerals. In limestone caves, flowstones are generally the most common type of formation. Curtains – These are formed when water droplets run along the ceiling of the cave and gradually form sheets of minerals. Lily pads – Lily pads are created when water droplets fall into a puddle and create a formation on the surface reminiscent of a lily pad. Helictites – Helictites are an unusual form of stalactite that grow with bends or angles in them that seem to defy gravity. Their strange growth style is most likely caused by capillary forces acting on the water droplets. Oolites –