Strumica (river) in the context of Novo Selo municipality

Strumica (Macedonian: Струмица, pronounced [ˈstrumit͡sa] ) is the largest city in southeastern North Macedonia, near the Novo Selo-Petrich border crossing with Bulgaria. About 54,676 people live in the region surrounding the city. It is named after the Strumica River which runs through it. The city of Strumica is the seat of Strumica Municipality.

The Struma or Strymonas (Bulgarian: Струма, romanized: Struma, pronounced [ˈstrumɐ]; Greek: Στρυμόνας, romanized: Strymónas, pronounced [striˈmonas]) is a river in Bulgaria and Greece. Its ancient name was Strymon (Greek: Στρυμών, romanized: Strymṓn, pronounced [stryˈmɔːn]). Its drainage area is 17,330 km (6,690 sq mi), of which 8,670 km (3,350 sq mi) in Bulgaria, 6,295 km (2,431 sq mi) in Greece and the remaining 2,365 km (913 sq mi) in North Macedonia and Serbia. It takes its source from the Vitosha Mountain in Bulgaria, runs first westward, then southward, forming a number of gorges, enters Greece near the village of Promachonas in eastern Macedonia. In Greece it is the main waterway feeding and exiting from Lake Kerkini, a significant centre for migratory wildfowl. Also in Greece, the river entirely flows in the Serres regional unit into the Strymonian Gulf in Aegean Sea, near Amphipolis. The river's length is 415 kilometres (258 miles) (of which 290 kilometres (180 mi) in Bulgaria, making it the country's fifth-longest and one of the longest rivers that run solely in the interior of the Balkans.

Parts of the river valley belong to a Bulgarian coal-producing area, more significant in the past than nowadays; the southern part of the Bulgarian section is an important wine region. The Greek portion is a valley which is dominant in agriculture, being Greece's fourth-biggest valley. The tributaries include the Konska River, the Dragovishtitsa, the Rilska River, the Blagoevgradska Bistritsa, the Sandanska Bistritsa, the Strumitsa, the Pirinska Bistritsa and the Angitis.

Strumica (Macedonian: Струмица, pronounced [ˈstrumit͡sa] ) is the largest city in southeastern North Macedonia and the country's ninth most populous overall, situated near the Novo Selo-Petrich border crossing with Bulgaria. About 54,676 people live in the city and its surrounding region. The city, which is the eponymous seat of the Strumica Municipality, is named after the Strumica River, a tributary of the Struma which runs through it.

Sandanski–Petrich Valley (Bulgarian: Санданско-Петричка котловина, romanized: Sandansko-Petrichka kotlovina) is situated in southwestern Bulgaria along the river Struma and its right tributary Strumeshnitsa, with a very small part of the territory extending to Greece. The valley is enclosed by several mountain ranges, three of them reaching heights of over 2,000 m, and is open to the Strumitsa Valley to the west and the Serres Valley to the south. Due to the proximity to the Aegean Sea, the climate is continental Mediterranean, making Sandanski–Petrich Valley one of the warmest regions of Bulgaria.

Administratively, it falls within Blagoevgrad Province, where it occupies its southwestern-most parts in is divided in four municipalities. It is named after the two most populous cities in the area, Sandanski and Petrich. The mild climate, numerous mineral springs and the abundance of natural and cultural landmarks within the valley and in its proximity favour agriculture, tourism and related industries. Sandanski–Petrich Valley has a strategic location at the border with Greece and the Republic of North Macedonia and lies on the shortest route between the capital Sofia and the Mediterranean Sea.