What is the longest lasting institution on earth?

In yesterday’s Gospel from the Mass (Matt 16:13-19), Jesus establishes something remarkable: [13] Now when Jesus came into the district of Caesare’a Philip’pi, he asked his disciples, “Who do men say that the Son of man is?” [14] And they said, “Some say John the Baptist, others say Eli’jah, and others Jeremiah or one of the prophets.” […]