Some couples dream of a private retreat for their honeymoon, but Thompson Island gets the party started early. The 204-acre preserve features views of the Boston skyline and three ceremony-site options, and soon-to-be spouses can opt for a tented reception with dancing and a four-course dinner or something less formal with a clambake, lawn games and a bonfire. The island also offers a private ferry and overnight accommodations for up to 160 guests.