The Blue stone is one of the few ritual things surviving from the time of the pagan Rus. At present the Blue stone is on the eastern side of Lake Pleshcheevo beyond the Nikitsky Monastery. It is 50 meters from the bank.

The local Finno-Ugrian tribe of Merya worshiped to the god Jarilo. However, they made no bloody sacrifices to it. The Blue stone, which was then at the foot of the Jarilo hill, was called so because of its blue glow. It was believed to be the heart of Jarilo. The Blue tone itself was decorated by flowers and the surrounding bushes – by ribbons. People did circle dances round it. The size of the Blue stone was 3х2 meters. It weighed 12 tonnes.

It could change color after the rain and glow in the darkness. These phenomena are explained by the chemical composition of the boulder. 

There are a lot of legends related with the Blue stone. Even when these places were settled by the Slavonic tribes, Kleshchin fell into decay, the town was moved to the mouth of the river Trubezh and paganism was long replaced by Christianity, the citizens of Pereslavl continued to held their feasts at the Blue stone. Of course, the churchmen didn’t like it.

They buried it in the ground, threw it in the lake but the Blue stone always reappeared on the bank. According to one legend, when a deacon buried the Blue stone, he got ill. But, according to the other legend, when the same deacon buried the Blue stone, he was cured of fever. The Blue stone was in the ground for some time and then appeared on the bank again. The water washed away  the slope and the Blue stone was pushed out  on the surface of the ground.

In 1788 they wanted to use the Blue stone as the foundation of the Dukhovskaya church. The church was built on the bank of the river Murmazh, a tributary of the river Trubezh, which falls into Lake Pleshcheevo, a little to the south of the Monastery of Boris and Gleb. The Blue stone was put on the big sledge and carried across the frozen lake. But the ice couldn’t withstand the weight of the stone and it sunk at the depth of 1,5 meters.

Seventy years later the Blue stone again appeared on the bank of the lake only a little to the north of its original location. The reasons of this phenomenon were long debated in the local paper.