I visited this WHS in December 2021 and spent 2 nights here to have ample time for taking photos at sunrise and sunset, at the WHS proper, from a distance and from high above, knowing beforehand that climbing the Pyramid of the Sun and of the Moon was forbidden as part of the COVID restrictions in place.

I would agree with Els that prohibiting tourists from climbing the pyramids will remain post-COVID, and it really isn't a bad thing at all. Like Uluru in Australia, the end result is a picture-perfect site for everyone to enjoy safely without the need of too many security guards, railings, etc and much restoration. Moreover, it is very easy to make up for the views from the top of the pyramids by joining a sunrise hot air balloon flight with one of the many companies providing the service. On a sunny day, the views over the empty pyramids, the platforms, the citadel and the avenue of the dead (without the pre-COVID crowds on the pyramids for sunrise).

Unlike Chichen Itza, all the structures at Teotihuacan lack the intricate sculptures and designs, except the Temple of the Feathered Serpent. This temple is an architectural delight almost half way through the avenue of the dead after the Pyramids of the Moon and the Sun. Unlike the steps with sculptures alternating the rain god Tlaloc and the feathered serpent heads, with long undulating feathered serpents in profile underneath them on the rear side, the temple, which is also the third largest pyramid at Teotihuacan, is not in such great shape. However, having visited the National Museum of Anthropology in Mexico City earlier, which has a whole impressive hall dedicated to Teotihuacan alone, I could compare the temple remains with what they must have looked like in the empire's heydays with the typical Mesoamerican use of red paint complemented on gold and jade decorations upon marble and granite. In the middle of its plaza lies a small structure with interesting tiny red mural paintings.

Always keeping in mind the incredible amount of Teotihuacan artefacts displayed at the National Museum of Anthropology in Mexico City and several other museums in Mexico and worldwide, the sheer size of the remaining repetitive structures of this WHS is really mind-boggling and is rightly considered one of the most architecturally significant Mesoamerican pyramid complexes built in the pre-Columbian Americas around 2,000-2,400 years ago. Teotihuacan was once the largest city in the pre-Columbian Americas with a population of around 125,000, making it at least the sixth largest city in the world. Apart from its outstanding pyramids, Teotihuacan's OUV lies in its city complex structure with well-preserved murals, which probably was the first planned urban settlement in Mesoamerica. There are small fragments of murals scattered around most structures in Teotihuacan: a puma with open jaws and large claws in the Puma Complex of the avenue of the dead between the two main pyramids, red geometric decorations inside the Quetzalpapalotl Palace and in the middle of the plaza near the Temple of the Feathered Serpent, and above all the splendid murals of the Tepantitla palace-like housing complex just outside of Gate 4.

The latter was probably inhabited by members of a priestly caste or by members of a leading family in Teotihuacan's society around 300-400 AD. It is really worth visiting, namely for the following murals: a red one of the rain god Tlaloc and another of Tlaloc's paradise in a setting full of butterflies, plants, springs and streams, then an elaborate and colourful one of a procession of priests dressed in beautiful clothes and plumed headdresses, depictions of people making use seeds and/or mushrooms with hallucinogenic properties, others of jugadores playing different kinds of ball games, as well as more murals of round shields and other priestly processions.

The best gate to skip the crowds in the morning is Gate 2 which is just in front of the Pyramid of the Sun. Morning light is perfect for viewing the Pyramid of the Moon and other nearby structures from here. Then you can proceed down the avenue of the dead, against the flow of most groups arriving late after breakfast at Gate 1 (just next to the entrance you'll find the UNESCO WHS plaque here). Parking at Gates 1 or 2 is also a wise choice if you intend to spend the whole day exploring this WHS (it's possible to go in and out on the same day with the same ticket). Towards closing time, you can continue to enjoy the Pyramid of the Sun in afternoon light till the very end as the right gates are just opposite. Make sure not to be far away near Gates 1 or 4 as you'll be invited to exit from the nearest gate, meaning you'll have to walk all the way round to your car! I really enjoyed my visit to yet another one of Mexico's top WHS on the WH list.