The Grand Avenue Tour at Mammoth Cave National Park is a 4-mile one-way hike underground that passes through several types of caves like slot canyons, tubular passageways, and tunnels sparkling with gypsum crystals all within Mammoth Cave. This tour of Mammoth Cave is the longest walking tour the park has to offer and lasts 4 hours.
The trail follows hundreds of steps (approx. 1,313) and ascends and descends many steep hills within the cave. Additionally, being in a cave can cause increased anxiety in some folks (myself included), which adds to the already-difficult walk that the tour follows. For example, upon entering, a large heavy metal door closes as you descend hundreds of stairs down a very steep and very narrow passageway to reach the first flat section of the cave tour.
Despite the tour being 4-miles one-way and ~4-hours long in total, it's a pleasant experience if you can get over being underground, and stuck there, for a long time. Note that this write-up is based on an experience 4-years old (we took the tour on April 30, 2018), but one part of the tour involved during out all of the lanterns to listen for noises we otherwise wouldn't notice in the complete dark. Things may have changed, but this tour may not be for some.
There is no GPS recording provided since it's impossible to get a satellite signal underground. After the tour I inquired with the national park if they had any GPS tracks for the Grand Avenue tour available, but did not hear back. Please see the photos provided for a better idea of what to expect on the tour.
Fees, Reservations & More Info
Please refer to the national park for more information on planning for this tour as it requires a fee and reservations. As of 2022, children must be at least 6 years old to go on this tour.
This tour ascends and desends 1,313 steps which on average is about 866 feet of elevation change to enter and exit the cave system. The calculations are approximate, but by the end of the tour, the hiker will likely gain and descend over 1,200 feet of elevation.
Lunch & Snacks
It's recommended to pack a lunch and snacks, plus plenty of water, for this 4-hour-long walking tour.