Το Σιδηρόκαστρο στο βιβλίο A HANDBOOK OF BULGARIA , 1920
A HANDBOOK OF BULGARIA Compiled by the Geographical Section of the Naval Intelligence Division^ Naval Staffs Admiralty An alternative road continues in a WSW. direction down the Oseno valley till it reaches its confluence with the Struma opposite Simitlii at mile 5. From this point there is a track up the 1. bank of the Struma joining the main Demir Hisar-Juma'-i-Bala road at the bridge 3 miles N. of Simitlii (see Route 26 at mile 74i). ROUTE 26 SERES—DEMIR HISAR—JUMA'-I-BALA, 83i miles This is one of the principal strategical routes, providing a line of entrance into Bulgaria via the Struma valley from the Salonica-Dedeagach railway at Demir Hisar. The light railway from Juma'-i-Bala was reported (Jan. 1917) to have been constructed as far as Rupel. From Seres to Demir Hisar is a good chaussee (according to report of March 1916) through open cultivated country. The soil is of hard clay and stony, providing good going in all weathers. From...