Cobbled Calle Mercaderes between Obispo and Plaza Vieja, four blocks south, is full of attractions. Setting out toward Plaza Vieja from the Hotel Ambos Mundos, after 20 meters you’ll pass the charming Museo de Ásia (Asia Museum, Mercaderes #111, tel. 07/863-9740, Tues.-Sat. 9am-5pm, Sun. 9am-1pm, entrance CUC1, cameras CUC2, videos CUC10) on your left, containing an array of carved ivory, silverware, mother-of-pearl furniture, kimonos, and armaments. Opposite, call in to the Pabellón de la Maqueta de la Habana (Model of Havana, Calle 28 #113, e/ 1ra y 3ra, tel. 07/206-1268, Tues.-Sat. 9:30am-6:30pm, adults CUC3, students, seniors, and children CUC1, guided tour CUC1, cameras CUC2); this 1:500 scale model of Habana Vieja measures eight by four meters, with every building delineated and color coded by use. Guides give a spiel.
On the west side, 20 meters farther south, the Casa del Tabaco houses the Museo del Tabaco (Mercaderes #120, tel. 07/861-5795, Tues.-Sat. 10am-5pm, Sun. 9am-1pm, free), a cigar museum upstairs.
At the end of the block, at the corner of Obrapía, the Casa de Benito Juárez (also called Casa de México, Mercaderes #116, tel. 07/861-8186, Tues.-Sat. 9:30am-4:45pm, Sun. 9:30am-1pm, entrance by donation) displays artwork and costumes from Mexico, including a collection of priceless Aztec jewelry.
Turn west onto Obrapía to visit the Casa de la Obra Pía (House of Charitable Works, Obrapía #158, tel. 07/861-3097, Tues.-Sat. 9:30am-5pm, Sun. 9:30am-noon, free), 20 meters west of Mercaderes. This splendid mansion was built in 1665 by Capitán Martín Calvo de la Puerta y Arrieta, the Cuban solicitor general. (The house and street are named for his obra pía, or pious act, of devoting a portion of his wealth to sponsoring five orphan girls every year.) The family coat of arms, surrounded by exuberant baroque stonework, is emblazoned above the massive portal, brought from Cádiz in 1686. The mansion features art galleries. Across the street, the Casa de África (Africa House, Obrapía #157, e/ Mercaderes y San Ignacio, tel. 07/861-5798, Tues.-Sat. 9:30am-5pm, Sun. 9:30am-noon, CUC2) celebrates African culture and is full of African art and artifacts. On the third floor is a collection of paraphernalia used in Santería.
One block east, between Mercaderes and Oficios, is the Casa de Oswaldo Guayasamín (Obrapía #112, tel. 07/861-3843, Tues.-Sat. 9am-5:30pm, Sun. 9am-1:30pm, free), housing a museum of art by the Ecuadorian painter, who lived and worked here for many years.
Next door is the Casa de los Abanicos (Obrapía #107, tel. 07/863-4452, Mon.-Sat. 10am-7pm, Sun. 10am-1pm, free), where traditional Spanish fans (abanicos) are hand-made.
Return to Mercaderes and pop into Habana 1791 (Mercaderes #176, tel. 07/861-3525, Mon.-Sat. 10am-7pm, Sun. 10am-1pm), on the southwest corner of Obrapía, where traditional fragrances are made and sold. Continue south half a block past the small Plaza de Bolívar to the Armería 9 de Abril (Mercaderes #157, tel. 07/861-8080, Mon.-Sat. 9am-5pm, CUC1), a museum that commemorates four members of Castro’s 26th July Movement killed in an assault on the armory on April 9, 1958.
One block south, the corner of Mercaderes and Armagura is known as the Cruz Verde—Green Cross—as it was the first stop on the annual Vía Crucis pilgrimage. Here is the Casa del Chocolate (tel. 07/866-4431, daily 9am-11pm), selling chocolates and featuring a museum relating the history of chocolate.