The Holy Mount of Grabarka (Święta Góra Grabarka in Polish) is considered to be the holiest location in Poland for Orthodox Christians. It is the site of The Church of the Transfiguration of the Lord and is home to the Female monastery of SS. Marta and Maria. The most prominent and well-known feature of Grabarka is the forest of crosses surrounding the Church bought to the Mount by pilgrims.
The of the Mount dates back to the 13th century, when during a Tartar invasion an icon of Spas Izbawnik was taken from the nearby church of Mielnik and hidden in the forests of Grabarka to prevent its theft or destruction.
A second miracle occurred at Grabarka in 1710 during a deadly outbreak of cholera in the region. According to legend, one day an old man received an order from God to lead the people to the Mount at Grabarka, to set there a holy cross and to pray for salvation. The sick villagers followed the instructions of the old man and the epidemic ended almost instantly. To commemorate this miracle the local people decided to build a chapel at Grabarka. 
In 1884-1895 a new church was built. After the First World War the church was in good condition. The church also survived the destruction that occurred to many buildings during the Second World War.
In 1947 with a blessing of archbishop Tymoteusz, a nun chose the Holy Mount for a Monastery of SS. Martha and Mary. Homeless sisters from monasteries which were closed down or situated behind the new borders of Poland took up residence there. In 1956 the second church of Icon of Mother of God “Happiness of All Crestfallen” with nun’s cells bordering on the church were consecrated. A house for priests serving at the Holy Mount was also built. During the 1960's The Church of Transfiguration of Christ was renovated. In 1980 a new brick monastic building with refectory of Dormition of the Mother of God were built.
In 1990 a tragic event took place a fire was set to the church of Transfiguration of the Lord. Fire completely consumed the temple, even the bells melted. Reconstruction started immediately, effect of which was consecration of a newly built church by Metropolitan Sawa on 17th May 1998.
The Holy Mount of Grabarka has been a centre for pilgrimage for Orthodox Christians from Poland and other countries since the 18th Century. The most significant of which is the Feast of the Transfiguration of Christ in August which draws about 100 000 believers from all over Europe. It is tradition for them arrive at Grabarka by foot, some of them bearing the wooden crosses that can be seen surrounding the Church.
http://www.grabarka.pl Official aebsite of The Holy Mount Grabarka
http://www.orthodox.pl/OrthodoxEng/glowna.htm Official website of the Polish Autocephalous Orthodox Church