What's a good 3-day itinerary for Cartagena?

Start before 8am. The humidity sits at 87% and 27°C feels closer to 33°C by mid-morning. The coral-stone streets inside the walls radiate heat through thin-soled shoes by 9am. Enter through Puerta del Reloj, the 1601 clock tower gate on Plaza de los Coches, while the plaza still smells of fresh arepas de huevo from vendors setting up. The Catedral de Santa Catalina de Alejandría sits 300 metres south on Plaza de Bolívar. Walk the nave, then continue 200 metres to Iglesia de San Pedro Claver and its cloister museum. Lunch at La Cevichería on Calle Stuart. The coconut ceviche runs 45,000 COP and arrives cold enough to fog the bowl. Afternoon heat peaks around 2pm. Sit it out with a limonada de coco at Café San Alberto on Plaza de San Pedro, where the cold glass sweats in your hand within 30 seconds. By 4pm the shadows lengthen enough to walk Plaza Santo Domingo. Dinner at Restaurante Interno in San Diego at 7:30pm, a 38,000 COP prix fixe run by inmates training for culinary careers.

Castillo de San Felipe de Barajas opens at 8am. Get there by 7:50. The fortress sits on Cerro San Lázaro, 1.5 kilometres east of the walled city. The Spanish started building it in 1536 and finished in 1657. Inside, the tunnel system stays cool even when the surface hits 33°C. You can hear your footsteps echo off walls three metres thick. Budget 90 minutes. From the castle, a 15-minute downhill walk drops you into Getsemaní. This is the neighbourhood where Cartagena's residents spend their evenings. Street art on Calle de la Sierpe and Callejón Angosto changes every few months. Lunch at La Cocina de Pepina. The mote de queso, a thick cheese-and-yam soup, costs 28,000 COP and tastes like it's been simmering since morning. Spend the late afternoon at Plaza de la Trinidad, where kids play fútbol under ceiba trees. Evening cocktails at Alquímico on Calle del Colegio, where rum sours run 35,000 COP.

Day 3 heads to Isla Barú. Boats depart from Muelle de la Bodeguita at 8am. The ride takes 45 minutes through the bay, past the fortress walls of Bocachica that have stood since the 1640s. Playa Blanca stretches 600 metres of white sand on the island's north shore. The water holds at 28°C and the salt dries on your skin within minutes. Rent snorkel gear for 20,000 COP from the huts at the beach's north end. Lunch at the fish shacks behind Playa Blanca's tree line. Fried red snapper with coconut rice and patacones runs 35,000 to 45,000 COP, and the smell of frying plantain carries 50 metres downwind. Return boats leave at 3pm and 4pm. You'll be back at the dock by 4:45pm. Walk through Centro Histórico at golden hour, when the colonial facades shift to burnt orange. Dinner at Carmen on Calle del Santísimo, where the tasting menu runs 280,000 COP.

Mind you, Centro Histórico covers barely 1 square kilometre, so the walking distances seem short on paper. But the 33°C heat index at 87% humidity slows everything to about 60% of your normal pace. Budget 40% more time per stop than you would in Barcelona or Lisbon. Taxis from the walled city to San Felipe cost 8,000 to 12,000 COP. Uber works but drivers sometimes cancel when they see a pickup inside the walls, where car access is restricted after 6pm. The sun sets at 6:15pm year-round this close to the equator, which likely means your dinner window opens earlier than you'd expect from a higher-latitude home city.