Directions:

The Observatory, where Ceres was discovered, is atop the Palazzo dei Normanni (Norman Palace) at Piazza del Parlamento, running south from Via Vittorio Emanuele - N38 06.69 E13 21.17.
The Cathedral is at the intersection of Via Vittorio Emanuele and Via Matteo Bonello - N38 06.83 E13 21.26.
The Old University (the location of the sciences before the 1930s), Via Maqueda - N38 06.89 E13 21.71.
The Institute of Experimental Physics (Royale Instituto di Fisica Sperimentale, now moved), Via Archiafi 36, where technetium was discovered - N38 06.61 E13 22.39.
Railway station, Piazza Giulio Cesare - N38 6.60 E13 22.02.
The historic meter conversion table on the wall (identified by "1"), found on Via Schiavuzzo - N38 06.85 E13 22.01