“After these things” refers us to the first discourse Jesus gave in this gospel, and it includes the things that happened after that. This same crowd will seek to have Him killed for claiming that He is the Son of God. Jesus decides to take a trip across the Sea of Galilee, a.k.a. Sea of Tiberias, Gennesaret, or Chinnereth in order to get some rest. This places Jesus on the eastern side (Gentile side) of the sea. This trip is about four miles. The crowd follows Jesus to the other side. They travel over land that was rugged, but that does not deter them. They even had to make it over the Jordan River to get to Jesus. This may have been the Golan Heights area.
It is an enormous crowd as the passage reveal. Even though they were following Jesus, this did not mean they were a spiritual group. They were following Jesus because of the miracles. Eventually, this crowd leaves Jesus (verse 66). He finds a place on the mountain where He and His disciples can rest. The Passover feast was getting ready to be celebrated.