Centennial Bridge towering above Soberanía National Park, Panama

Bridge of the world, heart of the universe. Celebrating Panama's independence

What do you get when you cross historic feats of engineering with unmatched natural beauty? Answer: This photo of a suspension bridge in a rainforest. Or more generally: Panama, where the photo was taken.

Panama celebrates its Independence Day today—although on this strategic, ocean-straddling strip of land, independence is complicated. When Panama broke loose from Spain on this day in 1821, it became part of Colombia until, backed by the US, it seceded in November 1903 just before the US took over construction of the Panama Canal. (The Centennial Bridge over the canal, shown here, was finished in 2003 and named to commemorate 100 years since Panama's secession from Colombia.) The US spearheaded building the international waterway, and controlled it until December 31, 1999, when Panamanians finally assumed full command of the canal, one of Panama's chief sources of revenue.