The holy spring is located between the village of Undory and the sanatorium named after V.I. Lenin, in a ravine. It was discovered by the blessed elder Anthony of Undory, who lived in Undory from 1870 to 1942. One day, he went for a walk in the forest with his eight-year-old nephew Nikita Ignatievich Kozlov. Anthony asked the boy to bring a mug, bread, and a shovel. When they reached the right spot, the elder pointed out to his nephew where to dig to find water. After the first strike of the shovel, water began to appear; after the second, the hole filled up, and after the third strike, a spring gushed forth. The water soon calmed down, and they scooped it up with the mug and drank the bread.

Over time, more and more people came to the spring, believing in the healing properties of its water. However, the spring was not equipped for the growing number of pilgrims. In the summer of 2005, with the blessing of the spiritual father of the women's monastery of Archangel Michael, Father Peter, the arrangement of the revered spring began. Initially, it was planned to make only a well, but Father Peter insisted on building a bathing area with a chapel. Despite concerns about the loose soil and the risk of landslides, he said: 'I bless.' Two months later, carpenters built a wooden canopy over the well and a closed bathing area with a baptismal font just below.