The monumental crypt, built by Tasziló Festetics in the honor of his wife, Lady Mary Hamilton in 1925, stands in the southern part of the Saint Nicholas Cemetery. The mausoleum was designed by Gábor Groffits and it is notable for its early use of reinforced concrete. The Neoclassical, arcaded structure with a tympanum can be approach by walking a set of stairs.

In the crypt under the mausoleum, four members of the Festetics family are buried: Lady Mary Hamilton; Count Tasziló Festetics; their child, György Festetics, and his wife, Mária Haugwicz who was originally buried in Vienna in the 1970's but her reinterment took place after the change of the regime. Glass tiles were put on the floor of the building, looking through them the crypt and tombs can be seen.

Near the mausoleum are the resting places for the servants and employeed of the Festetics family.

The building was neglected for many years and it was in bad condition, but it was restored to it's former glory in 2015. At the opening ceremony, even György IV Festetics was present.