Gigen is most famous for being built on the site of the important Roman colony of Oescus. The extensive ruins are located in the northwestern part of the village and were first associated with the ancient colony in the end of the 17th century. A bridge called built or reconstructed by Constantine I and named Constantine's Bridge in his honour used to link Oescus with Sucidava (modern Corabia) across the Danube in the 4th century.
Gigan is also known for an anti-Bogomil inscription in Old Bulgarian dating to the 10th century, the rule of Tsar Peter I of Bulgaria. The text was discovered in the old village church, inscribed on a stone block 85 centimetres in width. According to the scientifically accepted reading, the text of the inscription is as follows:
иже ... проч[ътет]ъ [еже нап]иса(х) [да проклъ]нетъ [ер]етика. аще бо и не про[клънетъ]. то д[а бѫ]детъ самъ проклѧ[тъ аще ж]е проклънетъ еретика. то [с]его бъ҃ гъ҃ помилоуетъ + се же писа анани мо[нахъ].
The one… who reads [what I wrote] [should curse] the heretic. If they do not curse him, then they shall be cursed themselves. Or if they curse the heretic, may God have mercy on them + So wrote the [monk] Anani.
As of September 2005 Gigen has a population of 2,611 and the mayor is Valeriy Damyanov. It lies at , at 39 m above sea level.