Complex sentence: He was awarded the grant "Villa-Medicis hors les murs" by the French Academy in Rome in 1987 which allowed him to establish himself in Naples where he started working on installations doing land-art on the volcanoes starting with the neighboring Vesuvius.
Split into simpler sentences: He was awarded the grant "Villa-Medicis hors les murs" by the French Academy in Rome in 1987. This allowed him to establish himself in Naples where he started working on installations doing land-art on the volcanoes starting with the neighboring Vesuvius.