I found this amazing website on AWOL this morning. It is still under construction, but what has been constructed is fabulous. It is a free-access online Encyclopedia of the Hellenic World (in English and Modern Greek). It is produced by the Foundation of the Hellenic World.
At the moment, there are three volumes which allow access: Volume I, Asia Minor; Volume II, Black Sea; Volume III, Constantinople. I have only browsed through a few entries in the Volume I, but thus far they look thorough and integrate pictures and links. I think these volumes are still unfinished, because nothing came up when I tried to visit Herodotus' page, but the project is encouraging.
If any of these sites come up in Greek, click the British flag button and they will change-over to English.