Helorus was an ancient Greek city of Sicily, situated near the east coast. It was probably a colony of Syracuse, of which it appears to have continued always a dependency. The name is first found in Scylax; for, though Thucydides repeatedly mentions the road leading to Helorus from Syracuse, which was that followed by the Athenians in their disastrous retreat, he never speaks of the town itself. It was one of the cities which remained the under the government of Hieron II by the treaty concluded with him by the Romans, in 263 BCE: and, having during the Second Punic War declared in favor of the Carthaginians, was recovered by Marcus Claudius Marcellus in 214 BCE.
Under the Romans it appears to have been dependent on Syracuse, and had perhaps no separate municipal existence, though in a passage of Cicero it appears to be noticed as a civitas. Its name is again mentioned by the orator (Id. v. 34) as a maritime town where the squadron fitted out by Verres was attacked by pirates: but it does not occur in Pliny's list of the towns of Sicily; though he elsewhere mentions it as a castellum on the river of the same name: and Ptolemy speaks of a city of Helorus.
Its ruins were still visible in the days of Fazello; a little to the north of the river Helorus, and about a mile from the sea-coast. The most conspicuous of them were the remains of a theatre, called by the country people Colisseo: but great part of the walls and other buildings could be traced. The extent of them was, however, inconsiderable. These are now said to have disappeared, but there still remains between this site and the sea a curious column or monument, built of large stones, rising on a square pedestal.
This is commonly regarded as a kind of trophy, erected by the Syracusans to commemorate their victory over the Athenians. But there is no foundation for this belief: had it been so designed, it would certainly have been erected on the banks of the river Asinarus, which the Athenians never succeeded in crossing.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.