Arcadius, AE4, 13mm 

Obv: DN ARCADIVS PF AVG, pearl-diademed, draped, cuirassed bust right
Rev: GLORIA REIPVBLICE, multi-level "campgate", with windows in an upper 
 layer and two turrets.
Mintmark: TES 
Ref: RIC IX Thessalonica 62 var.

This very unusual and unrecorded reverse may depict a tall wall with an 
open door and two windows, or the upper layer could be a building that 
was actually within the city walls (thus a 3D view).  Another possibility is 
that the lower layer represents the main gate in the city wall and the upper 
layer represents a section of the wall elsewhere that had 2 smaller doors 
(in 3D view). 
Within a week of this one turning up (causing great excitement amongst campgate collectors and for myself, when I identified it for the finder, who asked me whether it was worth cleaning or should he "chuck it" !!), another one 
with a little less detail was sold on ebay and is in the collection of Beastcoins. The example shown here is now in the collection of Ray Wilk.
Updated: This coin was for sale on consignment by Ancient Imports in April 2012.
Image used with permission of Ray Wilk (and Ancient Imports)

Contributed by Dane for Ray, Feb. 2005.