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        <FormAndLineReferenceDesc>SCHEDULE A, PART IV, SECTION A, LINE 1:</FormAndLineReferenceDesc>
        <ExplanationTxt>THE ORGANIZATION'S PURPOSE IS TO OWN, PRESERVE AND MAINTAIN REAL PROPERTY INCLUDING AN HISTORIC HOUSE AT 400 BEACON STREET IN NEWTON, MA, WHICH IS A FORMER RESIDENCE OF MARY BAKER EDDY, IN SUPPORT OF THE MISSION AND PROGRAMS OF LONGYEAR FOUNDATION, THE SUPPORTED 501(C)(3) ORGANIZATION WHICH IS DEDICATED TO ADVANCING THE UNDERSTANDING OF THE LIFE AND WORK OF MARY BAKER EDDY THE DISCOVERER, FOUNDER AND LEADER OF CHRISTIAN SCIENCE AND HER EARLY STUDENTS.</ExplanationTxt>
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      <CollectionUsedPubExhibitionInd>X</CollectionUsedPubExhibitionInd>
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        <DepreciationAmt>1830869</DepreciationAmt>
        <BookValueAmt>8816451</BookValueAmt>
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      <FootnoteTextInd>X</FootnoteTextInd>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>PART III, LINE 4:</FormAndLineReferenceDesc>
        <ExplanationTxt>THE BUILDING IS A HOME THAT WAS FORMERLY A RESIDENCE OF MARY BAKER EDDY. THE PURPOSE OF FOUR HUNDRED BEACON CORP OWNING THE BUILDING IS TO PRESERVE, MAINTAIN, AND OPERATE A HISTORIC HOME IN FURTHERANCE OF LONGYEAR FOUNDATION, THE SUPPORTED 501(C)(3) ORGANIZATION WHICH IS DEDICATED TO ADVANCING THE UNDERSTANDING OF THE LIFE AND WORK OF MARY BAKER EDDY THE DISCOVERER, FOUNDER AND LEADER OF CHRISTIAN SCIENCE AND HER EARLY STUDENTS.</ExplanationTxt>
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      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>PART X, LINE 2:</FormAndLineReferenceDesc>
        <ExplanationTxt>THE ORGANIZATION ACCOUNTS FOR UNCERTAINTY IN INCOME TAXES IN ACCORDANCE WITH ASC TOPIC INCOME TAXES. THIS STANDARD CLARIFIES THE ACCOUNTING FOR UNCERTAINTY IN TAX POSITIONS AND PRESCRIBES A RECOGNITION THRESHOLD AND MEASUREMENT ATTRIBUTE FOR THE FINANCIAL STATEMENT REGARDING A TAX POSITION TAKEN OR EXPECTED TO BE TAKEN IN A TAX RETURN. THE ORGANIZATION HAS DETERMINED THAT THERE ARE NO UNCERTAIN TAX POSITIONS WHICH QUALIFY FOR EITHER RECOGNITION OR DISCLOSURE IN THE FINANCIAL STATEMENTS AT DECEMBER 31, 2023. THE ORGANIZATION'S INFORMATION RETURNS ARE SUBJECT TO EXAMINATION BY THE FEDERAL AND STATE JURISDICTIONS.</ExplanationTxt>
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      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 11B</FormAndLineReferenceDesc>
        <ExplanationTxt>A COPY OF THE FORM 990 WAS PROVIDED TO THE BOARD OF TRUSTEES AND APPROVED BY THE AUDIT COMMITTEE BEFORE IT WAS FILED.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 12C</FormAndLineReferenceDesc>
        <ExplanationTxt>OFFICERS, TRUSTEES, AND KEY EMPLOYEES ARE REQUIRED TO DISCLOSE ANNUALLY INTERESTS THAT COULD GIVE RISE TO CONFLICTS.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION C, LINE 19</FormAndLineReferenceDesc>
        <ExplanationTxt>AVAILABLE UPON REQUEST.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART XII, LINE 2C:</FormAndLineReferenceDesc>
        <ExplanationTxt>THE ORGANIZATION HAS A COMMITTEE THAT ASSUMES RESPONSIBILITY FOR THE OVERSIGHT OF THE AUDIT OF THE ANNUAL FINANCIAL STATEMENTS.</ExplanationTxt>
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    </IRS990ScheduleO>
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          <CityNm>CHESTNUT HILL</CityNm>
          <StateAbbreviationCd>MA</StateAbbreviationCd>
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          <AddressLine1Txt>1650 MARKET STREET</AddressLine1Txt>
          <CityNm>PHILADELPHIA</CityNm>
          <StateAbbreviationCd>PA</StateAbbreviationCd>
          <ZIPCd>19103</ZIPCd>
        </USAddress>
        <EIN>046011948</EIN>
        <PrimaryActivitiesTxt>FUNDING FOR OPERATIONS</PrimaryActivitiesTxt>
        <LegalDomicileStateCd>MA</LegalDomicileStateCd>
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        <EntityTypeTxt>T</EntityTypeTxt>
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      <IdRelatedOrgTxblCorpTrGrp>
        <RelatedOrganizationName>
          <BusinessNameLine1Txt>EDWARD LONG ENDOWMENT TRUST</BusinessNameLine1Txt>
        </RelatedOrganizationName>
        <USAddress>
          <AddressLine1Txt>90 N MAIN STREET</AddressLine1Txt>
          <CityNm>CONCORD</CityNm>
          <StateAbbreviationCd>MA</StateAbbreviationCd>
          <ZIPCd>03301</ZIPCd>
        </USAddress>
        <EIN>026105159</EIN>
        <PrimaryActivitiesTxt>FUNDING FOR CONCORD HOUSE</PrimaryActivitiesTxt>
        <LegalDomicileStateCd>NH</LegalDomicileStateCd>
        <DirectControllingNACd>N/A</DirectControllingNACd>
        <EntityTypeTxt>T</EntityTypeTxt>
        <ControlledOrganizationInd>0</ControlledOrganizationInd>
      </IdRelatedOrgTxblCorpTrGrp>
      <IdRelatedOrgTxblCorpTrGrp>
        <RelatedOrganizationName>
          <BusinessNameLine1Txt>MOLLIE BABCOCK TRUST</BusinessNameLine1Txt>
        </RelatedOrganizationName>
        <USAddress>
          <AddressLine1Txt>19131 E BUCKSKIN COURT</AddressLine1Txt>
          <CityNm>RIO VERDE</CityNm>
          <StateAbbreviationCd>AZ</StateAbbreviationCd>
          <ZIPCd>85263</ZIPCd>
        </USAddress>
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        <PrimaryActivitiesTxt>FUNDING FOR OPERATIONS</PrimaryActivitiesTxt>
        <LegalDomicileStateCd>MA</LegalDomicileStateCd>
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        <EntityTypeTxt>T</EntityTypeTxt>
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      </IdRelatedOrgTxblCorpTrGrp>
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      <GiftGrntOrCapContriToOthOrgInd>0</GiftGrntOrCapContriToOthOrgInd>
      <GiftGrntCapContriFromOthOrgInd>0</GiftGrntCapContriFromOthOrgInd>
      <LoansOrGuaranteesToOtherOrgInd>0</LoansOrGuaranteesToOtherOrgInd>
      <LoansOrGuaranteesFromOthOrgInd>0</LoansOrGuaranteesFromOthOrgInd>
      <DivRelatedOrganizationInd>0</DivRelatedOrganizationInd>
      <AssetSaleToOtherOrgInd>0</AssetSaleToOtherOrgInd>
      <AssetPurchaseFromOtherOrgInd>0</AssetPurchaseFromOtherOrgInd>
      <AssetExchangeInd>0</AssetExchangeInd>
      <RentalOfFacilitiesToOthOrgInd>0</RentalOfFacilitiesToOthOrgInd>
      <RentalOfFcltsFromOthOrgInd>0</RentalOfFcltsFromOthOrgInd>
      <PerformOfServicesForOthOrgInd>0</PerformOfServicesForOthOrgInd>
      <PerformOfServicesByOtherOrgInd>0</PerformOfServicesByOtherOrgInd>
      <SharingOfFacilitiesInd>1</SharingOfFacilitiesInd>
      <PaidEmployeesSharingInd>0</PaidEmployeesSharingInd>
      <ReimbursementPaidToOtherOrgInd>0</ReimbursementPaidToOtherOrgInd>
      <ReimbursementPaidByOtherOrgInd>0</ReimbursementPaidByOtherOrgInd>
      <TransferToOtherOrgInd>0</TransferToOtherOrgInd>
      <TransferFromOtherOrgInd>0</TransferFromOtherOrgInd>
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  </ReturnData>
</Return>