The ruins at Teotihuacan are possibly the most spectacular in Mexico. They can’t be missed if you are visiting Mexico City. It’s best to get there early to avoid the crowds and the blazing mid-day sun. And bring water; some vendors sell water, but many of them don’t open until midday.
The Teotihuacan archeological site is easily accessed by bus. Buses leave the Terminal Autobuses del Norte approximately every 20 minutes. The bus terminal is located at the metro stop Autobuses del Norte.
The bus terminal is hectic, but things run smoothly. When you arrive at the terminal, walk left towards gate 8 and purchase a ticket from the Autobuses Teotihuacan bus line (approx. MX$45). Just say “piramides” to the attendant. They might offer a return ticket, but it’s easiest if you just by a one-way ticket (“sencillo“). (You will pay your return fare when you board the return bus.) You’ll pass through a metal detector at gate 8, then head towards platform 6/7. Typically, the time on your ticket indicates when your bus will be pulling into the terminal, not when it leaves. So if you’re there a bit early, you might have to wait for the current bus to leave before your bus arrives.
We took a 7:20am bus to Teotihuacan that took about 45 minutes (but could take longer depending on traffic). Our bus dropped us off at the main gate (gate 1), but some buses may drop you off at gate 2 (it does’t make a difference). The archeological site is not the final destination, so you have to pay attention and know when to get off. When you see large signs for the archaeological site (and pyramids in the distance), you’ll know it’s time to get off.
When leaving Teotihuacan, you will catch the bus from gate 2. You’ll probably encounter young men selling beverages along the side of the road. Politely decline, and they’ll point you to where you wait for the bus. Gate 2 brings you to a cross intersection. The bus will come from the right, and make a right-hand turn at the intersection (away from the Teotihuacan entrance). So you want to wait across the road, on the right. When the bus stops, confirm they’re going to Mexico City.
You’ll get to experience Mexico City traffic first-hand on the return bus ride. The return trip will take closer to 75 minutes. Many people will likely get off at the Indios Verdes subway station; we got off too to avoid the last leg of the bus ride.
For a good visual guide of this process, check out this site.