One of the most important remains of historical significance is the Sangarius Bridge (Turkish: Beş Köprü) built by Byzantine Emperor Justinian in 533 AD.

Historically, it was situated on the old military road from Constantinople (now Istanbul) to the east, connected, since the end of the 19th century, by a branch line with the Anatolian railway.

The native Muslims are Armenians and Greeks who gradually converted to Islam, and it should not be ignored that Turk households settled in the region.

Tank Pallet 1st Main Maintenance, one of the biggest Turkish defense contractors, and Otokar, a major manufacturer of buses and military vehicles, are located in Sakarya.

Other major industries in the city and its surrounding province include textile factories for silk and linen products.

Agriculture and forestry also form an important part of the city's economy, with the production of tobacco, hazelnuts (fındık variety), walnut-wood, cocoons and vegetables.

While Turkey is a developing country, the city of Adapazari renovated its infrastructure and industry after the 17 August 1999 catastrophic earthquake which left more than 18,000 casualties behind.

Adapazarı Kültür Merkezi (Adapazarı Culture Center), Ofis Sanat Merkezi (Ofis Art Center), and Sakarya Sanat Galerisi (Sakarya Art Gallery) are the main cultural institutions led by the municipality.

Even though Sakaryaspor is not always a permanent team in the Süper Lig, they have raised many of Turkey's best players, such as Hakan Şükür, Tuncay, Oğuz Çetin, Aykut Kocaman and many more.