Editing Bithynia (section)

==Description==
Several major cities sat on the fertile shores of the Propontis (which is now known as [[Sea of Marmara]]): [[Nicomedia]], [[Chalcedon]], [[Cius]] and [[Apamea (Bithynia)|Apamea]]. Bithynia also contained [[Nicaea]], noted for being the birthplace of the [[Nicene Creed]].

According to [[Strabo]], Bithynia was bounded on the east by the river Sangarius (modern [[Sakarya River|Sakarya river]]), but the more commonly received division extended it to the [[Bartın River|Parthenius]], which separated it from [[Paphlagonia]], thus comprising the district inhabited by the [[Mariandyni]]. On the west and southwest it was separated from [[Mysia]] by the [[river Rhyndacus]] and on the south it adjoined [[Phrygia]] and [[Galatia]].{{sfn|Chisholm|1911|p=12}}

It is occupied by mountains and forests, but has valleys and coastal districts of great fertility. The most important mountain range is the (so-called) [[Uludağ|"Mysian" Olympus]] ({{convert|8000|ft|m|abbr=on|disp=comma}}), which towers above [[Bursa, Turkey|Bursa]] and is clearly visible as far away as [[Istanbul]] ({{convert|70|mi|km|disp=comma}}). Its summits are covered with snow for a great part of the year.{{sfn|Chisholm|1911|p=12}}

East of this the range extends for more than {{convert|100|mi|km}}, from the [[Sakarya River|Sakarya]] to [[Paphlagonia]]. Both of these ranges are part of the border of mountains which bound the great tableland of [[Anatolia]], [[Turkey]]. The broad tract which projects towards the west as far as the shores of the Bosporus, though hilly and covered with forests—the [[Turkey|Turkish]] ''Ağaç Denizi'', or "The sea of Trees"—is not traversed by any mountain chain. The west coast is indented by two deep inlets, the northernmost, the [[Gulf of İzmit]] (ancient Gulf of Astacus), penetrating between {{convert|40|and|50|mi|km}} into the interior as far as [[İzmit]] (ancient [[Nicomedia]]), separated by an [[isthmus]] of only about {{convert|25|mi|km}} from the [[Black Sea]]; and the [[Gulf of Mudania|Gulf of Mudanya]] or [[Gemlik]] (Gulf of Cius), about {{convert|25|mi|km}} long. At its extremity is situated the small town of Gemlik (ancient [[Kios|Cius]]) at the mouth of a valley, communicating with the lake of Iznik, on which was situated [[İznik|Nicaea]].{{sfn|Chisholm|1911|p=12}}

The principal rivers are the [[Sakarya River|Sangarios]] which traverses the province from south to north; the [[Rhyndacus]], which separated it from Mysia; and the [[Billaeus]] (Filyos), which rises in the Aladağ, about {{convert|50|mi|km}} from the sea, and after flowing by modern [[Bolu]] (ancient Bithynion-Claudiopolis) falls into the Euxine, close to the ruins of the ancient [[Tium]], about {{convert|40|mi|km}} northeast of [[Heraclea Pontica]] (the modern [[Karadeniz Ereğli]]), having a course of more than {{convert|100|mi|km}}. The Parthenius (modern [[Bartın]]), the eastern boundary of the province, is a much less considerable stream.{{sfn|Chisholm|1911|p=12}}

The valleys towards the Black Sea abound in fruit trees of all kinds, such as oranges, while the valley of the Sangarius and the plains near Bursa and Iznik (Nicaea) are fertile and well cultivated. Extensive plantations of [[mulberry|mulberry trees]] supply the silk for which Bursa has long been celebrated, and which is manufactured there on a large scale.{{sfn|Chisholm|1911|p=12}}