Perhaps the most interesting and coolest - in more way than one - part of the Miller Brewery Tour in Milwaukee is a venture into the brewery's caves. Once used for storage and to keep the beer cold before refrigeration was invented, these caves are an awesome glance at a different time and place in Wisconsin. They're part of the full Miller Brewery Tour, which is $10 for those over age 21 and free for those younger and runs pretty much every half hour between 10:00 a.m. and 3:30 p.m. and then 10:00 am - 2:00 p.m. Sundays in the warmer months.

Miller Brewery is one of the most iconic parts of Milwaukee and folks all over the world identify that classic beer with our great state. Their brewery complex on Milwaukee's near west side dates back to around the time Wisconsin became a state and the big red Miller sign visible from I-94 is as much a sign of a trip into Milwaukee as Miller Park or the Milwaukee Art Museum.

The historic Miller Caves were actually first started by the folks that owned the Plank Road Brewery that stood here first. Charles and Lorenz Best dug the first sections of caves beginning in 1850. The tunnels went 62 feet below ground, with 36-inch-thick brick and limestone walls that were 15 feet wide and 12 to 18 feet tall.

Now a showpiece of Miller Brewery, the caves were dug for a specific purpose. Before the advent of refrigeration, they offered cool, consistent temperatures. That was important for storing the beer, but could also be a crucial part of the fermentation process. According to Miller history, the caves were used because the beer being produced was lager. The term 'lager' is derived from the German 'lagern,' meaning to stock or store.

The Bests sold the brewery to Frederick Miller not long after they started the caves and he continued their construction, eventually completing 600 feet of underground beer storage tunnels that could store 12,000 oak barrels. The caves maintained a consistent temperature, so large blocks of ice were cut from local lakes and brought in to help drop the temperature. In warmer months, the ice would be packed in hay or otherwise insulated to keep it from melting.

Unfortunately, soon after the caves were completed, mechanical refrigeration became widespread, making the caves somewhat obsolete.

The caves were sealed off in 1908 due to lack of use and the fact that some were leaking. They stayed that way for nearly 50 years as the folks around Miller who remembered that they existed retired and moved on. In the 1940s, the construction of an elevator shaft led to the "discovery" of the caves.

In the early 1950s, the caves were prepared as emergency shelters and stocked with water and blankets. Shortly thereafter, there was a push to get the caves cleaned up and usable and make them a part of the brewery tour that Frederick Miller's grandson wanted to offer at the brewery. Many of the caves had caved in or been filled up, but about one-third of the original caves were restored. Now you'll find historic displays and some of the old equipment they found when they unearthed the caves.

Far from a dingy, unappealing place, the caves are now one of the jewels of the brewery. They can play host to a number of special events as well as being one of the very last stops along the tour. It's a truly special and unique spot and we're very lucky to have the ability access it and all the history that it is home to.

The tour includes beer samples for those of age and a souvenir glass. There's quite a bit of walking on the tour and some mandatory stairs, so keep that in mind. For the most up-to-date information on when tours are happening, check out their Facebook page. For all the details on what the tour includes, head to the website.

Miller Brewery is located at 4251 W State St., Milwaukee, WI 53208. Tours leave from the visitor's center at the south end of the complex.