The Rock of Monaco is a 62 metre tall promontory overlooking Monte-Carlo's port and the Mediterranean sea. It is also the oldest of Monaco's areas, where the Old Town is located.
During the 6th century BC, Greeks founded the colony of Monoikos. Its name comes from Hercules, who was said to have constructed the ancient path that passed through the region from Spain to Italy together with Monaco's port and a coastal road. The road was, thus, dotted with altars to Hercules, and a temple dedicated to him was established on the Rock of Monaco.
Nowadays, the rock is home to Monaco's Old Town, with medieval narrow streets and the country's most important monuments: the Palais Princier, Saint Nicholas Cathedral and the Oceanographic Museum.
https://www.seemonaco.com/caves/rocher-de-monaco-rock-of-monaco-697184