The Brugal rum operation has been in Puerto Plata since 1888, and the bottling plant on the main road into town offers free tours that are more substantial than the typical distillery visitor experience. The tour takes you through the bottling and blending process, explains the company's particular approach to ageing (their rums spend time in both American and Spanish oak barrels), and ends — as you would expect — with a tasting. The guides are knowledgeable and the setting, a working industrial plant rather than a heritage attraction, has a certain honest quality to it.
Brugal is the dominant rum in the Dominican Republic by a significant margin; most of the rum drunk in the country, in everything from corner shops to resort bars, is Brugal. Trying it at the source, accompanied by an explanation of the different expressions, gives you a better framework for ordering it elsewhere. The Añejo is the baseline aged version; the 1888 is the premium tier. The tour is free but tips are customary. Check current hours before visiting as they vary by season and the tour may not run every day.