Tuckaleechee Caverns sit right in the centre of Townsend, about as convenient a cave visit as you will find anywhere in the Smokies. The cave system is genuinely impressive: a mile of well-lit passages open to the public, featuring one large "Big Room" roughly the size of a football field, with ceiling formations that include stalactites more than 20 feet long.
Guided tours last about an hour and cover the main passages and chambers. The temperature inside is a constant 58°F (14°C) year-round, which is a blessing in summer heat and a good reason to bring a jacket in winter. The lighting is designed to highlight the formations without overpowering them. Admission is charged; the cave is open daily from mid-March through November.
Tuckaleechee is one of the larger commercial cave systems in the eastern United States and makes a good wet-weather alternative when outdoor activities are rained out.