Early one morning in May 1999 I arrived, by overnight bus from Shiraz, in Shush, the town in Southern Iran nearest to Tchoga Zanbil. There it was very easy to find a taxi driver prepared to take me the 40kms or so, through semi-desert though once fertile country, to this site (prices in Iran were very low at the time of my visit).
The heart of this site is an impressive pile, of mud brick construction, said to be the largest surviving ziggurat in the world. Now, more than 3000 years after it was built, having been sacked by the Assyrians in 640BC and having spent most of the time since then buried in the desert sands it stands about 25m high. It has, however, been calculated that it was once more than twice this height having lost 2 of its 5 storeys over the years.
Some visitors might feel that some of the restoration has been a bit over enthusiastic, with large areas of obviously new brickwork on the lower parts of the structure, a process which was being continued, at a fairly gentle pace, when I was there.
I was surprised to find that I was allowed to climb all over the Ziggurat which stands on a low plinth measuring 105m on each side. There are the remains of a number of other structures including a large surrounding wall and others which were once royal palaces. I was particularly impressed by a water supply and drainage system which brought water from a site 40kms away (though why this was thought necessary given that we are on the tree lined banks of the river Dez here I was not able to establish).
After about two hours contentedly ambling around the site, at which I was the only visitor, I'd seen enough and so took my taxi back to Shush.
This remains the only ziggurat I have seen. I don't expect to see a more impressive one.