Photo courtesy Graycliff The Market at Graycliff will be back again this year. Visit local vendors from 5 to 8 p.m. Thursdays starting July 20 at Graycliff, 6472 Old Lake Shore Rd, Derby. Admission to the market is free. Each night there will be music and at 6 p.m. family yoga by Yoga Parkside. Stroll the grounds and see the gardens in bloom. For a $10 admission, take a self-guided tour of the main house. The producer-only Market at Graycliff…