Housed in a fine antique building that was once the Gran Hotel and later the French canal headquarters, this is the best museum in Panama City and an obligatory stop for every traveler. The museum is a study of the Panama isthmus — from pre-Columbian times, to the arrival of the Spanish, to the French and the American canal-building efforts, through the present day. The museum gives you a good understanding of the isthmus as the center of world trade; it also provides (somewhat subjectively) an explanation of the effect of the isthmus and the canal on the Panamanian identity.
Historical documents here include the 1977 Carter-Torrijos treaty that turned over control of the canal to Panama in 2000, multimedia and interactive exhibits, mock-household exhibits of everyday life during the history of the canal, a register of the U.S. Senate votes approving the canal, and a floor of old coins and stamps, including the famous Nicaragua stamp with an erupting volcano that was sent to senators to sway them from choosing that country to build a canal. This is an impeccable museum, with interpretive information in Spanish and English, and there are on-site guides who give bilingual tours. There are also an excellent library and a small cafe and bookstore, and the museum is wheelchair accessible. You could easily spend a full hour here.