Roman Athens 

Sulla, Cicero, Ceaser and Augustus 

Under Roman rule, Athens was given the status of a free city because of its classical period schools, and many Emperors visited Athens. Roman agora is still there today, after excavations of the American Archaeological school of Athens.

Roman agora monuments’ history 
The Tower of Winds building was built by the famous engineer Andronicus of Cyrrhus around 50 BC, but according to other sources, might have been constructed in the 2nd century BC before the rest of the Roman forum.
Athens first destruction after Persian Wars (since it was respected after Peloponnesian War), occurred during a siege in autumn 87 BC till summer of 86 BC. Roman general Sulla destroyed Athens because even respected from Romans, Athenians allied with King of Pontus, Mithridates. Romans managed to enter Athens at night. Dipylon was destroyed, Olympian Zeus temple the same, and both Plato’s Academy and Lycaeum.
Sulla robbed the city of some of its treasures. He confiscated gold and silver, probably from the Akropolis, and the contents of an entire library. Nevertheless, he honoured other friendlier Attica areas, like Amfiareion at Oropos, located at the east. Sulla also destroyed Piraeus, where you can visit its museum.

According to American Archaeological School of Athens (which is the main source for this data) Sulla also removed several columns from the unfinished Olympieion and transported them to Rome to be used in various temples on the Capitoline. Sulla’s soldiers also are reported to have removed the shields of past Athenian heroes from the Stoa of Zeus Eleutherios as spoils of victory. This marks the first known occasion that Romans despoiled the city by taking away the treasures and artifacts of Athens’ rich historical and cultural past, a practice that most certainly did not endear the Romans to the Athenians. It is difficult to judge the extent of the despoiling of Athens.

Before Sulla raid to Athens, in 79 BC, Cicero arrived to Athens (maybe to avoid Sulla in Rome), where he studies studied philosophy with Antiochus of Ascalon, the ‘Old Academic’ and initiator of Middle Platonism.
After battle of Pharsalos (48BC) Athens was visited by Caesar. Appian, moreover, records that Caesar rebuked the penitent Athenians by asking:

“How often will the glory of your ancestors save you from self-destruction?”

In fact, according to American School of Athens, the name of Caesar was held in such little esteem in Athens that upon his assassination in 44 B.C. the Athenians erected bronze statues of Brutus and Cassius next to the famous Tyrannicide group of Harmodios and Aristogeiton in the Classical Agora, which, after the Akropolis, was the most distinguished place in Athens for the erection of honorary statues. The memory of Caesar was apparently vilified by the Athenians.The Romans were generally viewed at best as rapacious, untrustworthy, and disrespectful of Athenian culture and democratic traditions, something can be noticed in Augustus relation to Athens.
Immediately following battle of Actium (31 BC) Augustus sailed to Athens where, as Plutarch informs us, he became reconciled with all the Greek states, and he stayed in the city long enough to participate in the Elefsinian Mysteries. He visited Athens in 19 and 12 BC and participated in Elefsinian Mysteries as well.

Apostle Paul and Emperor Hadrian 

The Greek Gods were still alive, and Elefsina was not yet destroyed.
Apart from Emperors, also Apostle Paul visited Athens in 51 AD, since there were also Jews and a Synagogue. In Athens Paul he found a city full of idols, meaning statues. Athens hosted numerous religions and monuments already, as one of the most tolerant to religions city of its times. Between 98-102 AD the Library of Pantainos is constructed in the Athenian Agora.
Especially Roman emperor Hadrian (Adrianou street today is named after him), visited Athens several times in the 2nd century AD, and constructed a library, a gymnasium, an aqueduct which is still in use, several temples and sanctuaries, a bridge and financed the completion of the Temple of Olympian Zeus in 117 AD, which was completed in 129 or 131 AD.
Another notable building was constructed during Roman period, the Odeon of Herodes Atticus, a stone theatre, located on the southwest slope of Acropolis. The building was completed in 161 AD and then renovated in 1950. Between 170-180 travel writer Pausanias writes about Greece.
The 3rd Athens destruction took place in the 3rd century. Athens was sacked by the Heruli in AD 267. After this raid, the city was hastily refortified on a smaller scale, with the Agora left outside the walls. The post Roman wall, dated around 276-282 μ.Χ. at that period the Beule gate on Acropolis was built, by which the Acropolis is accessed today, stands to the west of the Propylaia. Beule gate was built in the mid-third century AD as part of a program to protect the sacred precinct, possibly after the destructive invasion of the Herulians. Together with another gate located under the tower of Athena Nike, it was built into a strong fortification wall erected west of the Propylaia. The gate was named after the French archaeologist who investigated this area in 1852.

Athens Roman Epilogue 
Nevertheless, Athens remained a center of learning for almost 300 years more. In the next century, notable students as Gregory of Nazianzus, Basil of Caesarea and emperor Julian proves that Athens was still the top school of ancient world, and a center of Paganism.
Two destructions of Athens took place during Roman period. The 4th raid was by Alaric in 396, before sacking Rome in 410. He also destroyed Corinth, Megara, Argos and Sparta. Even though Christianity was a reality for Eastern Roman Empire (Byzantium), Christian items do not appear in the archaeological record until the early 5th century, oil lamps constructed by Athenian ceramists (tradition goes on till today).

Roman monuments of Athens today

Except from the Roman Agora, there is the pillars outside Saint Catherine church, and some baths near Irini church at Navarhou Nikodimou. Also Panathenaic Stadium and Hadrian Arch. A must-visit is Byzantine museum as well.