While building the town set in Belize, the crew unearthed an ancient Mayan temple. It notified the Belize government, which declared the site an important historical find.
River Phoenix was raised in the Children of God cult, where he and his family had been stationed in Venezuela. River was motivated to act in this movie because he recognized the many similarities between it and his childhood.
River Phoenix and Harrison Ford had a very close bond. Ford personally recommended Phoenix for the part of young Indy in Indiana Jones et la Dernière Croisade (1989) after working with him on this movie. Ford stated that of all of the young actors who were working at the time, River was the one who looked the most like him when he was that age.
During casting, River Phoenix was passed on several times for the role of Charlie Fox for being too old (he was fifteen). When no age-appropriate Charlie could be found, Phoenix's audition tape was brought in again to director Peter Weir and, impressed by Phoenix, he decided to put the age issue aside and give him the job.