There are a couple of small bars around the Plaza Bolívar. Of these, the Rasquatekey Bar and La Chuchera are the most popular. If you're looking for a mellower vibe, try Bar & Restaurant Acuarena or La Gotera. For a sunset cocktail, Bora El Mar, La Gotera, and the rooftop bar at Natura Viva are your best options -- but you'll want to arrive early as tables with views are limited. In general, hours of operation for bars are 4pm to midnight, although they are very seasonal -- some close during low periods and some will stay open as long as there are customers buying drinks.
