The Jardin Exotique de Monaco is a botanical garden located on a cliffside in Monaco. The succulent plants were brought back from Mexico in the late 1860s. By 1895, Augustin Gastaud, who served as the Chief Gardener of the State Gardens of Monaco, grew the succulents in the Jardin St Martin.
Albert I, Prince of Monaco acquired a piece of land in Les Moneghetti in 1912. He commissioned Louis Notari, the Chief Engineer of Monaco, to build a new garden with footbridges. During the construction, Notari found a grotto underneath in 1916.
The grotto was opened to the public in 1950, but it may only be visited with specialized guides. Evidence of prehistoric human inhabitants has been found in the cave. There is a museum of Prehistoric Anthropology within the Exotic Garden displaying many of those prehistoric remains. It was founded by Prince Albert I in 1902.
References:The ancient Argos Theater was built in 320 BC. and is located in Argos, Greece against Larissa Hill. Nearby from this site is Agora, Roman Odeon, and the Baths of Argos. The theater is one of the largest architectural developments in Greece and was renovated in ca 120 AD.
The Hellenistic theater at Argos is cut into the hillside of the Larisa, with 90 steps up a steep incline, forming a narrow rectilinear cavea. Among the largest theaters in Greece, it held about 20,000 spectators and is divided by two landings into three horizontal sections. Staircases further divide the cavea into four cunei, corresponding to the tribes of Argos A high wall was erected to prevent unauthorized access into the theatron and may have helped the acoustics, but it is said the sound quality is still very good today.
Around 120 CE, both theaters were renovated in the Roman style.