We had a 40th anniversary a couple of years back and made a celebration fair. Families were able to attend 40 stalls/activities getting a stamp at each and then putting their completed card into a prize draw. We had staff/small team take a stall. We also opened a time capsule and made a new ones. Students were invited to contribute to the new one. These were the bigger aspects but we included smaller aspects throughout the year. Hope those ideas help.
