Plock is the most important city and place in the World for the Divine Mercy.
On February 22, 1931, here in Plock, 26-year-old sister Faustina had her first and most important revelation of Merciful Jesus and His wish regarding establishing of The Feast of The Divine Mercy on the first Sunday after Easter.
"In my thoughts luminous trail on which Saint Faustina Kowalska prepared herself for the acceptance of the proclamation of mercy – the trail leading from Warsaw through Plock and Vilnius to Cracow" – these are the words of Pope John Paul II, who raised sister Faustina Kowalska from the Congregtion of the Sisters of Our Lady of Mercy to the altars on April 30, 2000. Approaching the Old Market Square in Plock it is possible to visit the Divine Mercy Shrine which is with purpose of numerous religious pilgrimages from entire World.
In the 100. anniversary of birthday of the sister in this a place stayed opened Museum of the Saint Sister Faustina Kowalska.
The will of Lord had been finally fulfilled, when the famous painting of the Merciful Jesus with the signature Jesus, I trust in You had been made, and the Polish Pope announced a new church feast – Divine Mercy Sunday on the first Sunday after Easter.
The Sanctuary of The Divine Mercy is placed in the house of the Congregation of the Sisters of Our Lady of Mercy in The Old Market Square, and inside it, a chapel with the painting of Merciful Jesus and the relics of St. Faustina.
In the square, the site of the apparitions, we can find a statue of the Merciful Jesus.
In the old bakery, in which Sister Faustina had worked during her stay in the convent of Plock (1930–1932), there is the St. Faustina Museum. It features numerous memorabilia and documents connected with the Polish saint and mystic. In the historic basements, there is a preserved bread oven, whereas in neighbouring rooms a kitchen and Sister Faustina’s cell had been recreated.

Original website - Official website of The Divine Mercy Shrine in Plock: