Simplify the following text for a Grade 9 native English-speaking person.
Original: It was n't until the explorations and discoveries of Antonio Santander Casselli , and Gene Savoy in the 1960s , however , that many came to see this site at EspÃ ritu Pampa as the real Vilcabamba of legend .
Simplified: It was not until explorations and discoveries in the 1960s , that many came to see this site at EspÃ ritu Pampa as the real Vilcabamba of legend .