Walden Pond, Mass. ? A walk around Walden Pond can take as long as you need.

It was to this peaceful New England lake that a remarkable individual from nearby Concord came to live alone, clearing a spot for a one-room cabin.

Henry David Thoreau — the man who urged us to “simplify, simplify” — immortalized Walden as the birthplace of the conservation movement.

Thoreau lived here between 1845 and 1847 — bathing in the pond in the mornings, the only person in sight — and wrote one of the most breathtaking books of early American philosophy: “Walden, or Life in the Woods.”

“I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived,” Thoreau wrote in “Walden.”

Today, Walden Pond is a treasure well maintained.

There are no billboards, the woods have been kept intact, the visitor’s center is unobtrusive. It is still peaceful, even though it is peopled with fishermen, walkers and families, and even though you can get there by car.

Designated a National Historic Landmark thanks to Thoreau, the 103-foot-deep glacial kettle-hole pond is today a 333-acre state reservation. Surrounded by 2,280 acres of woods — known as the “Walden Woods” — it is a perfect spot for reflection.

Surrounded by history

A woman and young boy take a walk around Walden Pond in Concord, Mass. It was to this peaceful New England lake where writer Henry David Thoreau cleared a spot for a one-room cabin, which he called home for two years.

Whether Thoreau is for you the quintessential ecologist or the first dysfunctional suburban kid, the pond he so admired remains timeless.

Walden is smack in the middle of American consciousness. No wonder: It’s smack in the middle of where the American nation began — in the pastures and woodlands outside Boston.

Down the road is Minute Man National Historical Park, where arguably the American Revolution started April 19, 1775, when American militia men — “minute men” — attacked British soldiers advancing on a stash of arms in Concord.

The combatants “met in a series of unplanned skirmishes along a 22-mile stretch of road that ran from Boston to Concord,” reads the national park’s Web site. “The events that occurred along the Battle Road would mark the beginning of a struggle between British authorities, determined to enforce the will of Parliament, and the people of Massachusetts, determined to retain their rights as English citizens. An American war for independence and self-government was born which would last more than eight years.”

Thoreau was born July 12, 1817, in Concord, the home of other American intellectual giants such as Nathaniel Hawthorne, Louisa May Alcott and Ralph Waldo Emerson.

He wound up on Walden after Emerson, a close friend and philosopher, let him build a cabin on a woodlot he owned there.

At Walden, Thoreau experimented in living independently as he sought self-fulfillment and closure after his brother’s death.

He grew beans, did the first survey of the lake and contemplated nature’s exquisite gallery. He wrote of Walden as an eye — “intermediate in its nature between land and sky” — and described it as “blue at one time and green at another.”

Besides “Walden,” Thoreau also drafted his first book during that fertile period, “A Week on the Concord and Merrimack Rivers,” a short tale of a journey he took with his brother in 1839.

Visitors can view a replica of Henry David Thoreau's one-room cabin at Walden Pond in Concord, Mass. Thoreau lived at the pond from 1845 to 1847 and used his time there to contemplate and write Walden,

Lessons still valid

A Thoreau reader will walk with a slow gait around the lake, mindful of the nooks and crannies of nature, pause to observe other visitors and wonder what the lake was like when Thoreau lived here.

Of course, it is best to have read Thoreau’s works to experience a sense of awe. But a venture to the pond can be, of course, a good reason to pick up Thoreau — whether for the first time or not.

The lessons of Thoreau, a schoolmaster in later years, are as valid as ever. Nuggets of thought jump from every page of his works.

“There is no more fatal blunderer than he who consumes the greater part of his life getting his living,” Thoreau wrote in “Life Without Principle.”

He left Walden in September 1847, and gave the house he had built in the woods to Emerson. It switched hands a couple of times — to Emerson’s gardener, and then to two farmers who turned it into a grain shed on the side of Concord. In 1868, Thoreau’s former home was taken down and used as scrap lumber.

Back in society, Thoreau continued working as a surveyor and pencil maker. He forged ahead with his studies and writing, and taught at the Concord Lyceum and elsewhere in New England.

His interests turned toward politics and social justice. He championed equality and blasted slavery. Indeed, his family helped runaway slaves escape to freedom in Canada.

His 1849 essay, “Civil Disobedience,” eventually brought him fame outside the United States.

The sparsely furnished replica of Thoreau's one-room cabin at Walden Pond is seen through a window which reflects, above, on ceiling, the outside surrounding woods in Concord, Mass.

“On May 6, 1862, at the age of 44, the self-appointed inspector of snowstorms and rainstorms and author renowned for motivating the world to value our natural environment, died after a prolonged struggle with tuberculosis,” says the state Web site on Thoreau and Walden.

Reaching Walden is a milestone for a traveler and a Thoreau admirer.

Questions about the genius of Thoreau will pop up anew: What did he intend when he chose to not pay the poll tax, a decision that landed him in jail? What were his priorities? And what should ours be?

At Walden Pond, the self reviews itself. And a walk around it is both puzzling and refreshing.