The Bacardí distillery in Cataño is the largest premium rum distillery in the world — the company moved here from Cuba after Castro nationalised the family operations in 1960 — and the visitor centre, Casa Bacardí, runs a slick set of tours that have become a standard San Juan half-day excursion.
You take the AcuaExpreso ferry from the Old San Juan terminal across the bay to Cataño (a five-minute ride) and then a short taxi to the distillery. The standard tour is a ninety-minute walk through the brand history with two free cocktails at the end; the mixology and rum-tasting tours cost more and are better. The ferry plus the views back across the bay to Old San Juan are themselves worth the trip.