Now in its 20th year, the Boston International Fine Art Show once again sets up shop at the Boston Center for the Arts’ Cyclorama building, bringing a wide range of art from many eras, genres and countries to the heart of the Hub’s South End. Beginning October 20 with a Gala Preview from 5:30–8:30 p.m. that benefits the Boston Athenæum, the show extends into the weekend, taking place Friday from 1–8 p.m., Saturday from 11 a.m.–8 p.m. and Sunday from 11 a.m.–5 p.m. Throughout this art extravaganza, patrons can browse masterpieces offered for sale by 40 galleries from across the U.S. and the U.K., and can also attend special programs, including an appearance by renowned maritime painter John Stobart on October 21 from 5–7 p.m. and a lecture on the Boston Athenæum’s current exhibit highlighting the work of famed Lincoln Memorial sculptor Daniel Chester French on October 22 at 2 p.m.