Filed Under Architecture

Diemer Mansion

Cleveland's Hidden Home

In a city with a history as rich as Cleveland, one would have no problem finding a building, landscape, or district recognized either nationally or locally for its historical significance. Places like the Terminal Tower, Rockefeller Park, or the West Side Market might quickly come to the minds of locals listing significant places in the area, or they may be found on the lists of tourists traveling to Cleveland. When driving down St. Clair Avenue on the city’s near-east side, these same individuals would undoubtedly notice the Slovenian National Home, the largest such cultural center of its kind in the United States. However, locals and tourists alike may be unaware that lurking behind this iconic cultural center is a mansion that has stood on the property for over a century.

Built around 1870, the Diemer Mansion was constructed for Peter Diemer, a German immigrant who relocated to Cleveland with his parents in 1840. Peter Diemer’s personal wealth was amassed thanks to his entrepreneurial spirit and business savvy. He began Cleveland’s first artificial ice company capitalizing on a growing national industry that would eventually lead to the downfall of the global Ice Trade of the nineteenth century. As owner of the company, Diemer's success allowed him to become one of the first individuals to purchase and develop land east of East 55th Street where his family would live for almost fifty years.

Though not as grand as the sprawling homesteads that would have been found along Euclid Avenue on Millionaire’s Row in Cleveland around the same time, the Diemer Mansion had a dominating presence along the St. Clair corridor. Situated on a sprawling estate, the two story home boasted many unique features which included an access road running along side it, known as Diemer Street, that provided direct access to Lake Erie for the family, now renamed East 64th Street.

The exterior of the home is derivative of the Colonial style with Italianate influences. Constructed of red brick, the front facade is perfectly symmetrical around the main entryway with two windows flanking the front door on either side. Four ionic columns support a one story portico and each window on the first and second story are accented with terra cotta keystones. Along the roof line is an ornamental wooden cornice supported by modillions which wrap around the entire structure. The triangular pediment in the center of the facade above the second story windows is surpassed in height on the home only by the cupola in the center of the roof.

Immediately inside the front door is the grand foyer with a staircase opened to the second floor. On either side of the staircase stands the parlor and dining room with two matching carved marble fireplaces. Arguably the most unique feature of the interior, though, is the second floor ballroom. To accentuate its grandeur, the ceiling of the ballroom was raised into the attic to match the room heights of the spaces located downstairs.

Aside from its significance to the house, the ballroom is also a meaningful space in regards to the Diemer family’s history with the home. In 1918, the ballroom was host to the family’s last social event held there for the marriage of Alma Diemer. Shortly thereafter in the same year, the Diemer family sold the home to the Slovenian National Home Organization. After purchasing the site, the group converted the upstairs bedrooms into classrooms where English classes were offered to immigrants from Slovenia who settled in Cleveland. The organization also excavated the basement to be converted into a private bar for members of the organization.

Today, the mansion remains surprisingly unaltered for a structure of its age, both inside and out. The Slovenian National Home did little to the home aside from the reconfiguration of the basement and the shortening of the first floor windows on the front facade. The home was also originally built with wooden shutters which the Slovenian National Home removed but have kept stored in the attic. In 1924, rather than demolish the mansion to make way for a much-needed expansion of the center, the Slovenian National Home had a new structure erected around the house, simultaneously preserving and hiding it away from the streetscape.

Traces of the Diemer family near the site are most readily observed by the renaming of an alley behind the Slovenian National Home now recognized as Diemer Court. In 1974, the city of Cleveland designated the mansion a historic landmark with the Slovenian National Home being identified as such a decade late in 1984.


The Diemer Mansion (Pre-1924) This undated photo of the Diemer Mansion shows how the property appeared when the Slovenian National Home purchased it in 1918. The exterior of the home remains largely unchanged aside from the shortening of the first floor windows on either side of the front entrance and the excavation of the basement for the Slovenian National Home's barroom. The new Slovenian National Home was erected around the mansion in 1924. Source: Slovenian National Home
The Diemer Mansion, 2014 The Diemer Mansion has largely been untouched since it was acquired by the Slovenian National Home in 1918. This photo shows the minimal exterior changes including the excavation of the basement for the Slovenian National Home's private bar and the shortening of the first floor windows on either side of the entryway. Source: Slovenian National Home
The Foyer Immediately inside the front door is the main foyer. The winding staircase leading to the second floor is anchored on either side by the dining room and parlor. Both spaces retain their original, matching carved fireplace mantles and are currently used as meeting spaces and offices by the Slovenian National Home. Source: Slovenian National Home
The Second Floor Ballroom The second floor ballroom is not only significant because of its square footage, but also because it is the space where the Diemer family hosted their last gathering, the marriage of Alma Diemer in 1918, prior to selling the property to the Slovenian National Home. To accommodate the height of the room, the ceiling was raised into the attic. Today, the space is used as a place for meetings of members of the Slovenian National Home. Source: Joe Dill Date: 2015
Hopkins Plat Map, 1881 This plat map from 1881 shows how underdeveloped the St. Clair corridor was when the Diemer Mansion was constructed (property outlined in red). Today, the house hidden by the Slovenian National Home is surrounded by densely packed industries, businesses and residential properties. Source: Griffith Morgan Hopkins, City Atlas of Cleveland, Ohio (Philadelphia: G. M. Hopkins, 1881). Date: 1881
Aerial Shot of Slovenian National Home Property This aerial photo illustrates the way in which the Slovenian National Home was constructed around the Diemer Mansion in 1924. In this image, the Diemer Mansion is denoted as the Slovenian Museum and National Archives. Source: Google Maps
The City Ice and Fuel Company The artificial ice company Peter Diemer originally founded became the City Ice and Fuel Company following a series of mergers after his tenure as owner. It was considered 'artificial' ice because it was made in large refrigerated factories rather than harvested in natural environments as was the case with ice captured and sold during the Ice Trade of the nineteenth century. Source: Cleveland Memory Project, Cleveland State University Library Special Collections



Joe Dill, “Diemer Mansion,” Cleveland Historical, accessed February 3, 2023,