The commune Sânzieni is situated in the northeastern part of Covasna county, in the Three Chair Basin (northern part), by the foot of the Bodoc Mountain, in the valley of the Casin River. It is situated 4 km from Târgu Secuiesc and 35 km from Sfântu Gheorghe, the administrative center of Covasna county. The commune is made up of the village Sânzieni with 2.720 inhabitants (in 2011), Casinu Mic with 261 inhabitants (in 2011), Petriceni with 954 people (in 2011) and Valea Seacă with 628 inhabitants (in 2011). The total number of the population reported in 2011 was 4.563 people. According to the data of the National Statistical Institute the total area of the commune is 9.670 ha, whereas the population density is of 48,09 persons per km2. The commune is situated at the foot of the Perkő Hill in the valley of the Casin River, which offers a marvelous touristic landscape and an excellent panorama on the hill. The commune offers to its visitors many attraction spots: the ruins of the Tarnoczy Castle, the Roman-Catholic Church of Sânzieni, built in 1401, the Village museum of Casinu Mic, the mineral waters from Casinu Mic, the mill from Valea Sand the Saint Stephen Chapel on the Perkő Hill. The special flora and fauna, the unpolluted fresh air of the forests from the area, neighborhood to the touristic resort Cătruşa.
- The Roman-Catholic Church, built in 1401 and fortified in the XV.-XVI. centuries.
- “Perkő” Chapel
- The local museum of Casinu Mic
- Recreation area Cătruşa
- Miner water fountain of Casinu Mic