There is a Jewish house of prayer, a public school and a hospital. The township is located on a flat stretch of unforested land, and is covered with black soil and clay. At one time this area belonged to the royal family. It was bequeathed in the year 1570 by King Zygmont August to Anne of Radzivil of Kishchyn, in the Vilno district, who upon her marriage to Krzysztof Sadovsky signed it over to him. The town was returned to the Radziwil family, who established here a protestant parish. In 1603 Laurentius Petrovius became the minister of the newly established parish.

In 1733 part of the Oszmiansky confederation, established on behalf of Stanislaw Leszczynsky, to oppose August III, experienced a serious setback. On February 9, 1839 Alexander Okinczyc was born here. In 1859 the town ownership was transferred to Count Zamoysky. In the year 1879 Sielec and Jundzilovicho (part of the Slonim district), 23,470 (dz) in area, were purchased by Golcz. Some of the Sielec properties are 7000 (dz) in area, of this 5000 (dz) is forested. The town also has two distilleries, two brick yards and a brewery. The Orthodox deanery of Sielec comprises 8 parishes, has 8 parish and 2 affiliate churches, 2 cemetary chapels, and 23,465 parishoners.