Mexico City is the reason the word metropolis exists! I recently traveled there for the second time with two of my friends who were going for the fist time. As we were flying over the city my friend just looked out the window mouth a wide open just repeating the words that's the biggest city I've ever seen! At 25 million plus on the metro area, she wasn't wrong. It has everything you want in a city, quaint neighborhoods like La Roma with great boutique shopping during the day and a hip bar scene at night. There are museums, you can't miss the Frida museum! There are lush parks! And the food there are no words. If you leave without eating something delicious you have done it wrong. There is something for everybody. As a Black American woman traveler I felt fairly comfortable. There are lots of expats in Mexico City and the people are beyond friendly. A little Spanish will go a long way, but it is easy to navigate without it for English speakers.