Exhibit 10.26


                          SECOND AMENDMENT TO LEASE
                          -------------------------

      THIS SECOND AMENDMENT TO LEASE (this "Second Amendment") is entered 
into as of the 1st day of June, 1998 by and between 6715 KENILWORTH AVENUE 
GENERAL PARTNERSHIP ("Landlord") and PATHNET, INC. ("Tenant").

                                 R E C I T A L S

      A.   Landlord and Tenant are parties to that certain Lease Agreement dated
August 9, 1997, as amended by that certain Amendment to Lease dated March 5, 
1998 (together, the "Lease").

      B.   Landlord and Tenant desire to add certain premises to the Lease 
and make certain other modifications to the Lease as more particularly set 
forth herein.

      NOW, THEREFORE, in consideration of the mutual promises of the parties 
and other good and valuable consideration, the receipt and sufficiency of 
which are hereby acknowledged, the parties hereby agree as follows:

      1.    PREMISES.  Paragraph 1 of the Lease is hereby deleted, and the 
            following paragraph is inserted in its place:

                  Landlord hereby leases to Tenant, and Tenant hereby leases 
                  from Landlord, upon the terms and conditions set forth in 
                  this Lease, the fourth, fifth and sixth floors in the 
                  building located at 1015 31st Street, N.W., Washington, D.C.
                  (the "Leased Premises"). The Leased Premises contain 
                  approximately 15,293 square feet.

      2.    TERM.  The initial term of the Lease is hereby extended until 
            May 31, 1999. The initial term remains subject to renewal as 
            provided in Paragraph 36 of the Lease.

      3.    RENT.  In Paragraph 3 of the Lease, (i) the number "$203,920.00" 
            is hereby deleted, and the number $305,860.00" is inserted in its 
            place; and (ii) the number "$16,933.33" is hereby deleted, and 
            the number "$25,488.33" is inserted in its place.

      4.    RATIFICATION.  Except as expressly modified herein, the Lease 
            remains in full force and effect in accordance with its terms.

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      EXECUTED, under seal, as of the day and year first written above.


                                       LANDLORD:

                                       6715 KENILWORTH AVENUE GENERAL
                                       PARTNERSHIP

                                       BY: /s/ David Schaeffer
                                          -------------------------------------
                                          David Schaeffer
                                          General Partner


                                       TENANT:

                                       PATHNET, INC.

                                       BY: /s/ William R. Smedberg
                                          -------------------------------------
                                          William R. Smedberg V
                                          Vice President, Finance and Corporate
                                            Development









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