The posted coordinates will lead you to the first stage of this two stage multi-cache. What you can find at stage one, with the help of a UV light, can help you find the final location and the large cache waiting there. Yup, ultraviolet light will be helping you, not giving you a sunburn.
UVB induces production of vitamin D in the skin at rates of up to 1,000 IUs per minute. This vitamin helps to regulate calcium metabolism (vital for the nervous system and bone health), immunity, cell proliferation, insulin secretion, and blood pressure. Which sound good, vitamins and stuff, but the UV flashlights cachers will be using to find this cache give off radiation in the 315–400 nanometer wavelength, or long wave Ultraviolet A.