Facebook founder Mark Zuckerberg is celebrating his fifth wedding anniversary somewhere in rural Maine.

The billionaire social media giant posted a notice Friday afternoon that he and his wife, Priscilla Chan, are taking their annual anniversary trip to the Pine Tree State.

He said that his original honeymoon got cut short so he promised Chan that they would make up for it by honeymooning on their anniversary every year.

“That brings us to today. Some years we’ve gone to Japan or France. This year we’re traveling around the U.S. and we’ll be spending our honeymoon in rural Maine,” Zuckerberg said.

Zuckerberg gave no hint of where he is in Maine. Most of the state is rural by anyone’s definition.

He is giving the commencement address at Harvard University on May 25 so he may just be relaxing a bit beforehand in one of the nation’s top tourism destinations.

Like any wise husband, he added, “One lesson I’ve learned from marriage is that exploring together just gets better over time.”

He said their wedding was held one day after Facebook’s initial public offering, which swelled Zuckerberg’s wealth.

They wanted a low-key wedding, he said, “so we decided to make it a surprise and have it in our backyard. I sent our friends and family an email telling them I was throwing a surprise party for Priscilla to celebrate her graduation from medical school. Since they thought it was a surprise for Priscilla, they kept it quiet. When they showed up at our home, I told them we were getting married. It was a great day.”

Back in January, Zuckerberg vowed to try to travel through much of the United States this year.

He said his goal for 2017 was to “have visited and met people in every state in the U.S. by the end of the year.”