Why you're going: To bump around the Caribbean coast in a raucous party bus.
Hit the town on a Wednesday night in Cartagena and you'll wonder if a time warp fast-forwarded you to Saturday. Surprisingly, hump day's the biggest party night of the week, with hoards of tourists, hawkers, and students alike lining the streets of the Getsemani neighborhood, particularly around Calle Media Luna, where cheap hostels and bars abound. Head just a block over to the Plaza de la Trinidad where even more people will be mingling and slugging street beers. When a liter of cerveza costs just $1.50, it's hard to say no. And to get some culture with your booze, hop on a Chiva bus to drink during an open-air city tour. It's not the safest thing ever, but it sure is a good time.
No matter the day of the week, it's nearly impossible to walk five minutes without having someone try to sell you... well, that stuff Colombia used to be famous for. Everybody's got a connection, and is willing to offer. Politely decline -- unless you're OK with potentially having police escort you to an ATM, where they'll pocket your max withdrawal as a tradeoff for not ending up in a Colombian prison.
When you need a break from all the partying, take a bus or taxi out to Playa Blanca -- a serene respite from a city built on having a great time.