What should I avoid in Cartagena?

The worst value in Cartagena is the all-in-one Playa Blanca and Islas del Rosario boat that touts sell between Muelle de la Bodeguita and Puerta del Reloj: you'll spend about an hour bouncing across the bay with maybe 40 strangers, stop at the Oceanario on Isla San Martín de Pajarales that you never asked for, then get two hours on Playa Blanca on Barú, where the sand is hot enough to sting your soles and every towel draws a vendor within minutes. Women offering a free foot rub on Barú will smear coconut oil on your shins before you've answered, then ask for COP 80,000 or more. Say no early and keep your feet under your towel. A better choice is a night on Isla Grande or a private lancha booked through your hotel, which costs more but gives you quiet and clear water. The dock charges its port tax separately and in cash, so carry small notes to Muelle de la Bodeguita.

Inside the walled Centro, skip the horse carriages lined up at Plaza de los Coches. By mid-morning the horses stand on asphalt above 30°C, and the drivers' quotes tend to rise once you're seated. Walk instead: from the gate to Cartagena Cathedral and on to Iglesia de San Pedro Claver takes under 15 minutes on foot. Skip dinner on Plaza de Santo Domingo too, where a waiter will meet you beside Botero's reclining Gertrudis with a laminated menu and ceviche priced for cruise passengers. Cross into Getsemaní and eat at Donde Socorro on Calle Larga, or buy an arepa de huevo from a street fryer near Plaza de la Trinidad for a few thousand pesos. It's crisp outside, with egg inside. The Palenquera fruit sellers in yellow, blue and red dresses will pose for a photo and then ask to be paid, so agree on a price before you raise the camera and expect around COP 10,000. Café del Mar on Baluarte de Santo Domingo charges resort prices for sunset cocktails, while the wall a few metres away is free and gets the same salty Caribbean breeze.

Cartagena's taxis run on whatever fare you agree before the door closes, so never get in without settling the number first. At Rafael Núñez International Airport, go straight to the dispatcher booth outside arrivals: it gives you a printed slip with your zone's fare, and the men you'll see inside the hall offering rides are not part of that system. Some drivers will swap your COP 50,000 note for a 5,000 and then claim you underpaid; at about 3,236 pesos to the US dollar, that costs you roughly US$14, so count your notes out loud in the cab. For cash, use ATMs inside Bancolombia or Davivienda branches rather than the street kiosks along Avenida San Martín in Bocagrande. After dark in Getsemaní, expect a cocaine offer within a block of Plaza de la Trinidad; always refuse, because these offers are sometimes set-ups that end in a police shakedown. TTDI rates solo-traveler safety at 5.8/10 (see the TTDI Solo-Safety Index), and most of that risk traces to scopolamine drugging linked to dating-app meetups and to drinks left unattended in bars on Calle del Arsenal.

October is the wettest month on Colombia's Caribbean coast, and by 6am today it was already 25.9°C with 94% humidity, which feels like 31.6°C and leaves your shirt damp. Afternoon storms can flood Calle de la Media Luna ankle-deep within minutes, so from about 2pm, plan to be indoors, for example at the free Museo del Oro Zenú on Plaza de Bolívar. Castillo de San Felipe de Barajas, begun in 1536, has almost no shade on its ramps, so arrive when the gates open and turn down the unofficial guides at the ticket line, who charge more than the audio guide. Skip swimming at Bocagrande, where the water near the city is murky and the sand is grey. The Volcán del Totumo mud-bath tour is overrated for a first trip; the masseur, the photographer, and the woman who rinses you in the lagoon each expect their own tip of a few thousand pesos.