The graveyard where my ancestors are buried is a small, overgrown field west of the Sesupe River, which wends it way through Marijampolé, a city of almost 50,000 near Lithuania’s border with Poland. On one side of the cemetery is a main road littered with Soviet-era apartment blocks, their cement weeping dampness; on the other is a utility plant. The cemetery itself is less a monument to the individuals resting there than to the idea of a Jewish graveyard in Lithuania: a dozen headstones ringing a hillock, the sole granite survivors of World War II, when Nazis and local collaborators not only killed 8,000 Jews in a bend of the Sesupe a couple miles south but also smashed to bits the memory of those who’d lived and died there decades before.A year ago, I sat in this graveyard, wondering what, exactly, I was supposed to feel. I had come to Lithuania as part of “The Frugal Grand Tour,” a 13-part weekly series I was writing for my New York Times column, The Frugal Traveler. That week in July, I was delving into my heritage, trying to track down any extant details about the great-grandfathers and great-grandmothers who had, at the turn of the 20th century, left Lithuania for the New World. For almost all of my life, I had known nothing of them or their parents—like many immigrants, they told their children little of the lands from which they’d come.Which meant that by the time I came along, only the most meager handful of names and anecdotes remained. Great-great-grandfather Miller, on my mother’s side, had 12 children and died when his beard got caught in the millworks. Also, our name, as we understood it, had once meant “big hat.” Elementary-school assignments to make family trees went nowhere (particularly since I had but one uncle and no close cousins), and I grew up wondering what it must be like to have a big family, a history that stretched back more than a few generations, an idea of where you came from besides the Massachusetts town you lived in, an identity tied to more than just secular Judaism, New England, and Star Wars.Thanks to the internet, I began to learn things. On Ancestry.com, my father located documents about our family’s arrival and early years in this country, including draft cards that, for the first time, spelled out the name of the town the Grosses had come from: Marijampolé. When I decided to go there as part of the Grand Tour, I contacted a Vilnius-based researcher, Regina Kopilevich, who had been recommended by a distant maternal cousin in Delaware. Following my tips, Regina started digging into the Czarist-era records of Jewish communities, and by the time I arrived she had assembled a dossier of birth, death, marriage, and work data. My name, she told me at our first meeting, at a courtyard cafe in Vilnius, was not Gross. It was Grossmitz, or Grossmütz—Yiddish for “big hat.”At first, elation: finally! I existed in a way I never had before—back into the 1820s. The excitement lasted days, as Regina and I pored over the records together and visited the Holocaust memorial outside Vilnius, where we got distracted from the death pits by the wild strawberries and raspberries growing at the edge of the paths. Even though Regina hadn’t been able to find the birth records of my great-grandfather Morris (né Moshe), the Grossmütz who moved to Connecticut, I maintained my optimism as I boarded a train heading for Marijampolé.It was really only when I’d reached the cemetery that I began to sense the limits of this brand of “heritage tourism.” Here I was, sitting at the graves of my forefathers, nibbling the maple candy bar Regina had given me, but was I any different? The facts I’d learned had helped me—somewhat sketchily—to understand the world Morris had been born into and left behind, and now I could answer with precision when relatives of my wife, who is Taiwanese, asked where I’m from.But—and this is putting it crudely—so what? There are no family-tree assignments in my immediate future, and at the ripe old age of 35, I’m comfortable basing my identity on the here and now. Judaism matters little to me; it’s a vestigial organ, a curiosity.Which is not to say that Jewish history in Marijampolé, in Lithuania, and beyond does not interest me. The sudden violence with which the Nazis moved in, the easy acquiescence and hearty participation of Lithuanians in the killings, the eventual deaths of something like 95 percent of the country’s Jewish population—these are details that stun, appall, and fascinate me as a professional explorer of the world.These are also details that I learned not from traveling to Lithuania (though that provided the occasion for my education) but from books and websites, such as JewishGen.org. Even the facts that Regina dug up did not have to be delivered in person; email, though less dramatic, might have been as effective.In fact, were I to have built my knowledge of Lithuania’s Jewish history on what I could learn on the ground, in Vilnius and Marijampolé, I might know much less than I do. Outside of its Holocaust memorial and the Jewish graveyard, there are few signs that Jews ever inhabited Marijampolé—no museum, cultural center, synagogue, or historical society. And while in Vilnius I learned the broad sweep of Litvak history at the Vilna Gaon Jewish State Museum—from the tolerance of Jewish communities in early Lithuania to the Haskalah, or Enlightenment, to the artistic community that flourished between the wars—there was little I couldn’t have learned in the comfort of my own home in Brooklyn.In other words, when it comes to digging into the past, travel is not necessarily your best shovel. As Jews, we have a wealth of countries, languages, traditions, and histories to investigate, and one of us has likely written about a book about it already. No need to fly halfway around the world—to museums whose store of knowledge and exhibit design pale in comparison to the Vilna Gaon Jewish State Museum’s, to Holocaust sites devoid, for various reasons, of details and context, to the poorly marked graves of our ancestors.I know it’s weird for a travel writer to be saying this. Well, it’s doubly weird for me to find myself in the company of some ultra-Orthodox Israeli rabbis, who recently decried March of the Living, a series of trips for teenagers to Polish Holocaust sites, as a waste of time. “To understand what is anti-Semitism and why they hate the Jewish nation there is no need to travel abroad,” Dov Lior, the chief rabbi of Hebron and Kiryat Arba, told the Forward. Rabbi Shlomo Aviner, who runs a Jerusalem yeshiva, concurred: “There is no mitzvah at all to see historical places.” Instead, Aviner said, teens curious about the Holocaust should read books. It pains me to agree with them, but they may be right.Of course, these rabbis see Poles as irredeemable anti-Semites, and view any Jew’s departure from Israel—even if it’s to visit the place where a relative was murdered—as at worst a shande, at best a pointless detour from God’s path.But I also think they’re worried about what teenagers (and even grown-ups) will learn if they visit Poland, Lithuania, or anywhere outside Israel. For while travel is often a clumsy instrument for researching the past, it’s unparalleled for examining how the past and present come together in unpredictable ways.Take Jonas Oskinis. A friend of a friend of friend, Jonas was my unofficial guide through nighttime Vilnius, when the sidewalk cafes along Gedimino Prospekt opened and the beer began to flow. A public-relations representative for Lithuania’s national health system, Jonas was a big guy with a taste for apple brandy, basketball, and Lithuanian history, and over the course of several evenings we drank too much and talked a lot. Marijampole, he explained, was a town whose reputation he knew well—it was the birthplace of the modern Lithuanian press. But at the same time, he knew almost nothing of its Jewish community, and my search for roots impressed him. For Jonas, who had recently become a certified tour guide simply because he wanted to know his city better, the extent of Jewish history in Lithuania was a revelation, something that had, in various ways, been hidden from him. (“When I was young,” he wrote me recently, “there were no Jews or Lithuanians, just Communists.”)It was through Jonas that I learned of the country’s ongoing struggle to come to terms with its own history. The state prosecutor’s office, for example, was going after one of the few surviving Jewish partisans for the deaths of Lithuanians during World War II—while at the same time neglecting to pursue actions against Lithuanians who participated in anti-Jewish crimes. This, I imagine, put Jonas in an odd position (certainly odder than my alignment with ultra-Orthodox rabbis): he loved his country and because of that love wanted to understand it better, but he also saw his openness met by an increasingly superstitious, conspiracy-minded wing of society. Was that, for him, a greater tragedy than my inability to weep at the graves of ancestors?In any case, it was Jonas who was most eager to see me succeed in my quest, and who gave me a souvenir copy of the book The Jews of Lithuania. What would Rabbi Lior have said, to see a Lithuanian delve into Jewish lore?It can be argued that this is what rabbis like Lior and Aviner are afraid that Jews will discover—that new generations throughout Eastern Europe are putting historical enmities behind them, embracing a more honest version of history and learning about Jews, Judaism, and themselves. They—or at least almost all the people I’ve met in Lithuania, Poland, Romania, and Germany—are tolerant and forward-looking, and that is dangerous for all who cling to power in Israel by demonizing the outside. Better to stay home with one’s books, they say, read only one version of history and go on living in the past, whether the biblical era or, say, pre-Haskalah Lithuania. Today, however, when one can fly to Gdansk as easily as to Chicago, that’s an attitude that can’t survive long.In the meantime, I’m engaging in a new form of heritage tourism. As I write this, I’m spending a week at my parents’ house on Cape Cod, where my wife and I are introducing our seven-month-old daughter to my younger brother (whose wife is of Italian and German extraction) and sister (whose boyfriend is half-Jewish—the wrong half, if you care about such things). We’ve been going to the beach, eating lots of shellfish, and generally having a great time creating memories, the kinds of memories that, I hope, can’t be destroyed by knocking over a few tombstones.Matt Gross writes the Frugal Traveler column for The New York Times.