Puerto Rico – or Borinquén, as the island's pre-Columbian inhabitants called it – commands a pivotal spot in the Caribbean, the last substantial island before the sprawling arm of the Antilles swoops south towards Venezuela, fragmenting into the tiny Leeward and Windward Islands. Puerto Rico's unique status as a commonwealth of the US, however, keeps it a world apart from its island neighbours, over a distance that can be measured not just in kilometres, but in dollars. It's a place that combines island life with a level of infrastructure seldom seen in the region: excellent interstate highways allow travellers to zip from coral reef to five-star restaurant, and hikers can traipse through the spectacular El Yunque rainforest on well-paved trails maintained by the US National Forest Service. American influence is strongest in San Juan, where even the ramparts of El Morro – which staved off European aggressors for 500 years – haven't managed to prevent the influx of American fast-food and retail chains. But the capital's core retains a distinctly Latin character, with Old San Juan host to a treasure-trove of pastel Spanish colonial architecture on exquisitely restored cobblestoned streets.