The Wullenweber Antenna is used for High Frequency radio Direction Finding (HFDF). It is a type of Circularly Disposed Antenna Array (CDAA) that's also known as a Circularly Disposed Dipole Array (CDDA). It had been nicknamed as the elephant cage. They were designed to receive radio signals between 2 and 32 MHz.
Most were built after WWII with the majority built in the Soviet Union and aligned countries. The antennas in the Soviet Union were called Krug (Russian for circle). There were numerous other designations used throughout the world such as FIX8, FIX24, Thick8, and others.
The U.S. military designations for the antenna and associated equipment was AN/FRD-9 (Army and Air Force), AN/FRD-10 (Navy), and AN/AX-16.
Drawings of antenna construction
These two drawings taken from Wikipedia illustrate the physical construction of the antenna and the dimensions:
Locations
The map below shows the location of all the CDAA antennas including the Wullenweber, Krug, and variants. If it's a circular, high-frequency direction finding antenna, it's intended to appear on this map.
FLR-9 
AX-16 
KRUG 
FIX8 
FIX24 
FIX40 
THICK8 
Misc 
Sources
Youtube: The Last Elephant Cage