Complex sentence: This discovery was put in a museum prepared for the occasion, the Museum of Portici, annexed to the Accademia Ercolanese, founded by Charles in 1755 to house the findings from the excavations of Herculaneum.
Split into simpler sentences: This discovery was put in the Museum of Portici, built for the occasion, and annexed to the Accademia Ercolanese. The museum was founded by Charles in 1755 also to house the findings from the excavations of Herculaneum.