I managed to get ahead of myself yesterday and had not finished reading the article before posting this. Current hypothesis on the original wall is that it stood 12 feet tall, was 200 feet long, and contained 25,000 words; this is extrapolation from the discovered fragments. The discovered fragments criticize the Stoics, and argues the Gods are indifferent to human affairs. Archaeology does provide a short online slide show of this site.
A final quote from Diogenes (the article is not entirely clear as to whether it’s from the inscriptions or another source), concerning his motivations for setting up the wall:
Not least for those who are called foreigners, for they are not foreigners. For, while the various segments of the Earth give different people a different country, the whole compass of this world gives all people a single country, the entire Earth, and a single home, the world.
– Diogenes of Oinoanda
