ATOP MOUNT FUJI, Japan — Search for “Top of Mt. Fuji” on Instagram, and you’ll discover thousands of posts documenting the hikers who have made it here to the summit of Japan’s best-known volcano.

But for many trekkers, sharing photographs of their feat on social media is way too new school.

Instead, they would rather send an old-fashioned piece of snail mail from the tiny post office atop Mount Fuji, one of the few places in Japan where a postmark is still more coveted than another “like” on Instagram or Facebook.

“We thought it would have more meaning,” Toshiyuki Kasahara, 43, said of the postcards that he and his two sons, Yushun, 8, and Seijin, 6, deposited in the mailbox to send home after arriving on the summit last month. “It’s a substantial record that they can keep.”