In 1843 Thoreau and a friend walked the distance from Concord to the summit to take in the vista. In a line from his essay "Walk to Wachusett," he writes, "From the foundation of a wooden observatory, which was formerly erected on the highest point, forming a rude hollow structure of stone, a dozen feet in diameter, and five or six in height, we could see Monadnock, in simple grandeur, in the northwest, rising nearly a thousand feet higher, still the far blue mountain." They camped overnight and ate wild blueberries and milk, and read Virgil and Wordsworth by the light of the moon. There is no camping now but the mountain trails are accessible throughout the year.