The Lemp Mansion was installed with three room-sized, walk-in vaults, each measuring 13 feet high, 15 feet wide, and 25 feet deep. When the Lemps left town for the weekend, they placed their paintings, jewelry, and other valuables into one of the vaults, until they returned.

The Lemp Mansion was just as impressive underground as it was above. A tunnel ran between the house and the brewery. Utilizing a portion of Cherokee cave, the Lemps built an auditorium, ballroom, and swimming pool, that could also be reached from another tunnel (now sealed) that led out from the basement of the mansion. The swimming pool was heated year round using hot water piped-in from the boilerhouse at the brewery, located a short distance away.

Like the Lemp family, the Lemp Mansion itself suffered a decline in the years after Prohibition. In the mid 1960's, a substantial portion of the mansion grounds and one of the two carriage houses were lost to the construction of the Ozark Expressway, now called Interstate 55. After Charles Lemp's death in 1949, the mansion left the hands of the Lemp family, and it suffered further in the years it served as a boarding house, until being rescued in 1975 by the Pointer family, who have since restored it.

With all of the suicides in the Lemp Mansion, it is not surprising that the house would have a haunting reputation. But is it really haunted? Well, a few years ago, a part-time tour guide, strolling around the Lemp Mansion Restaurant after closing hours, reported suddenly hearing horses naying, and rustling, the noises seeming to originate from just a few feet outside the north side of the building, down from where William J. Lemp, Sr., had kept his office. Galloping to the window, the tour guide was distressed to find no horses anywhere in sight that night. Perhaps it is only a coincidence, but shortly thereafter, when the parking lot was expanded closer to the north wall of the Lemp Restaurant, evidence was unearthed that the area where the ghostly horse cries had originated from had once been used as a tethering lot for horses!

Others, from restaurant employees to renovators, have reported unusual phenomena happening in the mansion as well. An annual haunted house is held during Halloween in the Lemp caves, taking advantage the ghoulish Lemp reputation.

At one time, the Lemp Mansion was thought to have a "zoo" in some of the carriage house buildings. The rumor was started by neighborhood citizens, who frequently heard unearthly howlings at night, especially during full moons. The truth is that the noises were not coming from an exotic animal, but from a relative suffering from schizophrenia, who was in the care of the Lemp family.

Today, the Lemp Mansion is both a restaurant, and a bed and breakfast. Patrons can have a leisurely meal in one of the rooms in which William J. Lemp, Sr., or William J. Lemp, Jr., committed suicide, while awaiting their ghostly appearances.