the ZócaloConsistently the top recommendation for visitors, and worth allowing a half day rather than squeezing it between other stops.
Local culture beyond the checklistthe pyramids at Teotihuacán and Xochimilco's canals are where Mexico City feels least like a tourist itinerary and most like the actual city.
A well-known second stop: Chapultepec ParkRounds out a first visit nicely alongside the bigger-name sights.
Easy onward travelMexico City's transport connections make it simple to extend the trip into the rest of Mexico if you have the time.