Unfortunately, invaders, conquerors and occupiers besides being murderers are also looters and destroyers and the Spanish conquistadors committed all these atrocities..on steroids.
The Spaniards destroyed the larger temples or pyramids of this ancient city of Tlatelolco so they could use the stones from them to build the church that you see in the background of the first pic above.
Tlatelolco is called the Place of Three Cultures because what's visible to the naked eye as soon as you set sight on the place is ... the Aztec culture of almost 800 years ago via what's left of their pyramids which formed a part of their ancient city, and right behind the ruins is seen the Santiago de Tlatelolco Catholic Church, built by the Spaniards with stolen Aztec materials and then you see the buildings of modern Mexico lining the streets behind the church.
We strolled down those streets and walked into the grounds of some of the many housing complexes and they looked a lot like some we have here in Canada.
Archeologists are finding more artifacts and tombs in the grounds of this ancient city and parts of the site are under tents (see last pic) where the digging for past history continues.
If you want to learn more, go
here and here.