Mode of transportation: by rental car, from Queretaro en route to Puebla
Review and experience
Padre Tembleque Aqueduct is a unique WHS monument, and relatively unfrequented given it's slightly out of the way for most visitors. Rather than making a day trip from Mexico City and/or Teotihuacan, we took a slight detour en route from Queretaro (after several days in San Miguel de Allende and Guanajuato) to Puebla.
While the structure is impressive and the lack of visitors provided a quiet refuge after a lengthy and congested drive, I found the OUV of the aqueduct more limited in depth than most other WHS I have visited. Criterion (ii) is likely the most appropriate among Criteria (i), (ii) and (iv), considering it truly is an interchange of several cultural traditions, though that argument can be made for many cultural sites throughout Mexico constructed in the colonial times. I think it would have been equally if not more interesting to have featured a Mesoamerican aqueduct as a stand-alone WHS, as for example, the Aztecs built extensive water management systems, and I found featuring this aqueduct as a stand-alone site somewhat Euro-centric. All said though, the site was visually impressive and the history behind it interesting. I am also grateful for its being listed as a WHS, as otherwise it would have been very unlikely that we made a detour to visit!
Tactically, it was a little confusing getting to the location. GPS is relatively accurate, though it's easy to miss the dirt road that leads to the aqueduct. There is a nice security guard at the entrance, but otherwise no facilities (water, restroom, designated parking spot). Given a lack of gates, I imagine this site is open 24 hours, which is a nice bonus!