Museo Postal Cubano
Just east of the etching of Che Guevara and around the corner from Ministerio de Comunicaciones (Communications Ministry), you'll find this museum dedicated to the Cuban postal service. As well as documenting the history of the country's postal service, it also displays hundreds of stamps from all over the world, old Roman and Greek tablets dating as far back as the year 2300 BC, letters, and old seals. Keep a look out for Cuba's postal rocket, a unique experiment which was carried out in 1939.