Well, I won't keep you on hold any longer, we're now going into the classical period - and chances are good that we'll stay here for quite a while. I always get the feeling that 90% of all Greek finds are from this period, and I believe that they actually do make up a big portion of the archaeological remains.
Anyway, the Parthenon. Posting it as my first picture may be a little mainstream but it is, no doubt, the most well-known ancient monument from this period. You may remember that I mentioned a little while ago that another temple was under construction right before the Persian wars, being destroyed when Athens was taken. It was decided after that incident that the acropolis should be kept in it's ruined state to remind the Athenians about the disaster, but that was a policy difficult to keep up with as the city grew richer and more powerful. Thus is 447 BC a new temple was begun as a part of the major building program by Perikles in the city at this time. It (the cella, or inner central room, and cult image) was dedicated in 438 BC and the pediment sculptures in 432 BC.
There are, of course, an infinite number of details I could mention here, measurements, architectural curiosities and anecdotes, but that is for yourself to find out if you're interested. And I encourage you to do so.