This 30 meters high rock hill was used as guard hill in the Middle Ages. If enemy ships were seen coming from the sea, fire was lighted to the hill to warn local people. After the great fire in Turku (1827), instruments and astronomical books of Turku University observatory were transferred to Helsinki.
The Helsinki astronomical observatory was built to the hill in 1834. It designed in cooperation by professor Friedrich Wilhelm Argelander and architect Carl Ludvig Engel. The observatory was among the most modern astronomical observatories of its time, and served as an example for several European observatories that were built afterwards. A separate tower was built in the observatory garden for the telescope designed for astrophotography. This building was finished in 1890.
At the top of the hill is is also situated Stigell’s monument Haaksirikkoiset (“shipwrecked”), erected in 1898. The sculpture is stretching to the west and increased the national spirit in the end of the 19th century.
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.