Graffiti art covers a wall in the pedestrian-friendly Coyoacán neighborhood.

San Diego is unique in that just minutes away, literally, is an entire other country. The contrast is stark: neighboring Tijuana isn't the most beautiful and prosperous city, and contrasts greatly with a city like San Diego, most of which is relatively clean and well-off.

Mexico can consequently have a bit of a stigma. If you venture south and dig a little deeper, however, you might be pleasantly surprised to discover that the country's capital, Mexico City, is a cosmopolitan and culturally rich place. Yes, there's pollution, traffic, crime and poverty. But in many neighborhoods, you wouldn't even know it.

And with an expansive, efficient metro system, getting from Point A to Point B is pretty simple.

Getting around

Starting out at the large, modern main airport, there's a bus that costs a mere 30 pesos ($1.50) that runs directly to the city center. The bus is clean and safe. I disembarked in the historic centro, where I'd booked my accommodation at a youth hostel, steps away from the famous Zocalo plaza.

During the daytime hours the entire area is bustling with locals, Mexican tourists and lately, more and more gringo tourists. And by Latin American standards, it's pretty safe here, compared to cities like Rio de Janeiro, for example. At night it empties out a little, so common sense must be exercised – but staying on the main streets, you should be fine.

Riding the efficient metro, you can get out and explore different neighborhoods, filled with beautiful, interesting streets, tucked away between massive traffic-choked boulevards.

The metro requires some level of physical health, as the transfers between lines (within the stations) can be long. Vast corridors and up and down stairs just to make a basic transfer. It's best to avoid rush hour, but otherwise it's fine – and often quite entertaining. There will likely be a procession of various vendors selling random stuff and various buskers entertaining (?) with music or performance art, including one guy who would throw himself onto crushed glass and somehow not injure himself.

Subcultures and neighborhoods

What intrigued me during my first visit to this city was just how many different subcultures there are, from punk rockers to hipster artists to rappers to whatever scene or clique you can think of. This is quite contrary to the stereotypes many Americans have. Mexican immigrants to the U.S. are often from poorer rural areas of the country.

More Coyoacán graffiti art.

Neighborhoods like Polanco, Condesa, Roma, San Angel and Coyoacán are extremely charming and rather well-off, with historic, brightly painted buildings alongside tastefully done modern architecture, interesting shops and cafes, leafy streets lined with trees and bougainvillea, people congregating in the various plazas and, needless to say, excellent food at reasonable prices.

Returning to the Centro, the main plaza known as the Zocalo is vast and massive and beautifully preserved, along with the historical civic buildings that surround it. It's the site of numerous events and political rallies and whatever else, with its huge Mexican flag in the center. The streets running off from here have various restaurants and bars, ranging from stylish places to dubious-looking (but fun) spots situated up on the upper floors of random buildings.

Of course, with a city of its size and scale dealing with decades of corruption that still exist across the country to this day, there are obviously problems still being resolved. For one, air quality is often suffocating - no need for an Asian-style face mask, but still, some days are worse than others.

And certain neighborhoods should be avoided. You can emerge from a metro station and feel like you're in a completely different world. Not necessarily dangerous, but kind of run-down and shabby and disordered. When you emerge from the Cuatro Camihos station, for example, beside the various food and drink stands you'll find slot machines and their happy sound effects and down-and-out-looking clientele.

After four trips to Mexico City now, I have a blast every time, and there's still lots more to discover. A soccer match at the massive Azteca Stadium is definitely on the list.

But continuing on with your travels, there are many other destinations accessible via inter-city bus - and these inter-city buses are of exceptional quality and service, putting Greyhound to shame.