After six years on the job, executive director Lindsay Diehl will be retiring from the Wenham Museum on July 13. Diehl, who began visiting the museum as a child, served as marketing director from 1998 to 2001, and rejoined the museum as interim director in May 2006. She was named executive director a month later. “Her tenure has been marked by increases in visitation, programming, membership, and regional awareness as well as improvements in collections care and financial stability,” the museum said in a prepared statement.