The Grand Canyon
The Grand Canyon was a geological formation in Arizona, USA on Earth.
Captain Archer asked T'Pol she had visited the Grand Canyon or the Big Sur Aquarium during her assignment on Earth. She had not, stating that sightseeing was not part of her assignment. (ENT: "Broken Bow")
While surveying an uninhabited planet, Enterprise's initial scans discovered a gorge on the southern continent five times deeper than the Grand Canyon. (ENT: "The Catwalk")
In 2377, when Seven of Nine believed she was dying, the Grand Canyon was among the many fascinating places on Earth she wanted to see, but thought she never would. She was looking at pictures of it in astrometrics with Captain Janeway, whose father called it the biggest ditch on Earth. (VOY: "Imperfection")