The Frederick Law Olmsted National Historic Site is offering two free walking tours of the neighborhood where the famous landscape architect — designer of Central Park in Manhattan and Boston’s Emerald Necklace — moved his family and business in 1883. “Olmsted’s Brookline Neighborhood, Part 1” will start at 10 a.m. next Sunday, when a National Park Service ranger will lead a 1-mile walk with stops including the Brookline Reservoir, the Olmsted historic site at 99 Warren St., and the Walnut Street Cemetery. The second installment will take place Aug. 11. The tours are free, but participants must reserve a spot in advance; call 617-566-1689, ext. 221, Wednesdays through Sundays. For details, visit www.nps.gov/frla.