Brachot 54 - Blessings on miracles
One who sees a place where miracles were performed for Jewish people should say "Blessed are You, God, our Lord, King of the universe, Who performed miracles for our ancestors at this place" - just as Jethro did, who said " Blessed be God, Who rescued you from the power of Egypt ..."
This means that one should say a blessing on a miracle for the masses, but what about a private miracle? There was a certain man traveling through the desert on the south of Euphrates, and a lion attacked him. A miracle was performed for him, and he was rescued from the lion, and Rava told him to say "Who performed a miracle for me in this place."
So too, Mar the son of Ravina was going through the valley of Aravot, thirsting for water, and a miracle was performed for him: a well was created, and he drank from it. At another time he was in the marketplace of Mechoza, and a wild camel attacjed him. However, a wall of a nearby house fell down, and he entered the house, thus escaping the camel. In both places he would say a blessing!? - True, one is obligated to say the blessing for this, but the others are not; however, for the miracle done for the masses all are obligated to say a blessing. Other cases include a seeing rock that Og wanted to throw on the Jewish people, or the stone on which Moses sat during a battle with Amalek.
In general, four events deserve a blessing: crossing a sea, a desert, being sick and recovering, and being in prison and then released. All of these cases are described in psalm 107 . The blessing should be said in the presence of ten people, two of them being Torah scholars, because the psalm says, "Praise Him in the assembly of wise elders."
Art: Pieter Cornelisz. van SLINGELANDT - A Kitchen Scene with a Maid Drawing Water from a Well