The venue is located in the center of Athens, across from the Temple of Olympian Zeus and a short walk from the Acropolis and the new Acropolis Museum. The Acropolis and the Acropolis museum are the top-visited sights in Athens, and definitely worth making room for in your schedule.
Other suggestions for sights in Athens:
The ancient agora and the Roman agora are both well-worth a visit. (There’s a 30-euro 5-day package ticket for the Acropolis + all other open archaeological areas, including the two agoras, which is worth purchasing if you are definitely seeing more than just the Acropolis itself. You’ll have the luxury of walking around Athens and entering nearly anything that looks interesting.)
The National Archaeological Museum is a bit further away, but hosts an excellent collection. Of particular interest to a computing audience, it houses the Antikythera mechanism, a highly-complex ancient analog computer, much analyzed in recent years.
There are many more nearby sights (and nearly all Athens sights are a short walk or metro ride away). The historical center, including the much-photographed Plaka neighborhood, lies within a 4-minute walk. Walking around the entire Acropolis hill (including the edge of the Plaka and of the ancient+Roman agoras) is a common Athenian treat. Syntagma Square, the modern heart of Athens, is 1 km away, with the Parliament building and Athens’s main pedestrian shopping street, Ermou. Other nearby attractions include the vibrant Psirri and Koukaki neighborhoods and the posh Kolonaki neighborhood.
Getting around: the “Acropoli” Metro stop is a 3-minute walk. The coast is some-35 minutes away by public transportation (including the coastal tram).
The Athens International Airport is at 35 km. To get from the airport to downtown Athens, your options include:
The X95 bus: an inexpensive option, at 6 euro, which can get crowded during the day, as well as take longer due to traffic. Get your ticket from the airport curbside booth before riding.
The metro: at 10 euro, it is a reasonable and reliable option, but runs only twice an hour (airport departures on the whole and on the half hour), and has no service between midnight and early morning.
Taxis: convenient but pricey, at 38 euro during the day, 54 after midnight. Night trips from the airport are a particularly bad deal: the bus will be almost as fast and a fraction of the price during after hours.
Google maps should be good for giving you exact estimates, including walking distances.