Every third Sunday after Pentecost, Sacred Heart Fires are lit along the mountain ridges all across the South Tyrol. The spectacle can be seen from afar and attracts many onlookers. This old custom, which was variously named midsummer fires, Christian Johannis fire and finally, during the Napoleonic era in 1796, the Sacred Heart Promise.

The tradition of the mountain fires actually dates back to pre-Christian times but in 1796, by the time Napoleon's army had reached the Alps, the light of the fires was turned into the Sacred Heart alliance. When faced with the threat of war, the Tyrolean parliament decided to entrust the country to the care of the "most holy heart of Jesus" in the quest for Divine redemption.