Simplify the following text for a Grade 8 native English-speaking person.
Original: Burnham together with Charles Frederick Holder , in 1908 , made important archeological discoveries of Mayan civilization in this region , including the Esperanza Stone .
Simplified: in 1908 , Burnham with Charles Frederick Holder , discovered ruins from a Mayan civilization that had been nearby . One ruin they named the Esperanza Stone .