The picture on the left is an interesting example of how the latest generations of GSM and UMTS base stations are replacing legacy equipment in the field. Previously there were two base stations at the same place (one for GSM and one for UMTS) taking up most of the space of the gray plateau. The small base station now in place is about 1/5 to 1/6 the size of the two original cabinets and includes GSM and UMTS elements plus the equipment necessary for the microwave backhaul.
The refresh cycle is also interesting. I would estimate that the original GSM base station was in place for around 6 years and the UMTS base station for around 3 years. With the original GSM base station probably having been end of live, I guess it was a smart move to replace both at the same time. What I also noticed was that for two of the three radio sectors, the original two antennas, one for GSM and one for UMTS, were replaced by a common antenna including remote electrical tilt (RETA) for later fine tuning.
And finally, compare the size of this GSM and UMTS base station to much bigger VDSL cabinets, which are deployed with the same or even higher density as wireless base stations these days (I estimate their distance to be about 500m). Interesting to contemplate about the synergies and deployment costs.