There are many versions of a sightseeing tour in Athens. Whether by bus, by bike or by foot - there will certainly be something for you.
Here is a brief overview of the many options and the professional providers.
A Half Day in Athens! What to do?
How to spend 24 hours in Athens?
What you can do in 36 hours in Athens?
Hop-on Hop-off Buses in Athens
Athens Sightseeing Trains
Athens Segway Tours
Athens Travel Agencies & Services