My mother had been diagnosed with Alzheimer's. My father's response was to start traveling. Not to new places, but to the ones that had made my mother who she was. He wasn't following a guidebook. He was following the map of her memory.

Their first trip was to Kingsdown, Kansas, a town so small it barely appears on a map. My mother had lived there as a teenager while her father, a Presbyterian pastor, held a post in the area. She'd left as a junior in high school, leaving behind her best friend, Doris Marie, and a place she always said made her feel like she belonged.

By the time my parents arrived, decades later, Kingsdown had lost its post office and most of its population. A few houses and a grain elevator were about all that remained.

But Doris Marie was still there. She'd married a classmate, raised a family, and lived on a large farm. Her husband had passed. The two women were thrilled to see each other.

My father drove my mother past her father's church, past the house where they'd lived, to the places where teenagers used to gather. Each one brought something back. My mother recalled stories she hadn't told in years, and she told them with delight. My father watched, visibly moved.

The second trip was to Toccoa Falls, Georgia, a small city in the Blue Ridge foothills where my mother's parents had met as students at a Christian college. Both had enrolled planning to become missionaries. Instead, they found each other and eventually became pastors together.

My parents visited the campus, drove past my great-aunt Elsie's house, where she'd lived her whole life, and walked through places that were meaningful not to my mother directly, but to the people who shaped her. If Kingsdown held her own memories, Toccoa Falls held her parents' story.

The third trip reached even further back. My parents joined my sister and her husband on a visit to Scotland, where my mother's relatives had once lived. In Braemar, a village in the Cairngorms, they visited a cottage that had belonged to family. Robert Louis Stevenson stayed in that cottage in 1881, writing Treasure Island.

Then they traveled on to the Isle of Skye. My mother stood in that landscape and told my father it was the most beautiful place she had ever seen, that she would have been happy to live there for the rest of her life. She said she felt closer to her family than she ever had, that she understood her relatives in a way she hadn't before.

I wasn't on any of these trips. I know them through my parents' telling and my sister's, through conversations that gathered weight each time they were repeated. What I know most clearly is what my father said afterward. He told me, more than once, that those trips were the most meaningful travel of their lives.

In his 2002 book The Art of Travel, the writer Alain de Botton observed that we have no shortage of advice on where to travel but hear almost nothing about why we should go or how we might be changed by going. Most of the travel industry has never caught up, but my father, late in his life, didn't need the book. He wasn't seeking novelty or luxury or escape. He was doing something more deliberate: using places to reach the person he loved.

Each trip moved further back in time. My mother's own girlhood, then her parents' youth, then the ancestral landscape of Scotland. And at each stop, something came through. The places held what she needed, even as the disease was working to take it away.