Imper is situated 44 km far from Miercurea-Ciuc along the no. 121G county road. The settlement has closely grown together with Plaiesii de Sus. It is regarded as the oldest village in Tinutul Casinului. The only landowner of the village, József Balási, was the government official in charge of Tinutul Ciucului, Gheorgheniului and Casinului (he died in 1855). In 1992, Imper had 461 inhabitants, with the exception of 104 Romanians and 9 Gyspsies they were all Magyars. Besides farming and breeding they also practise wood processing. The village used to have several wood-mills in between the two world wars. The tiles made by the inhabitants were also famous.
To the northeast is a mineral water spring of which water is used to cure gout.
In Casinu we can notice the stone gates of the noble families, the dove-cotted gates of the well-off soldier families as well as the so-called 'foot-gates' of the poorer Szeklers and the settled serf families. We can also see several houses with eaves, large barns and gates. Opposing this, at the end of the century there appeared the peculiar settlement of the Csángó sheperds with scattered houses in the place of the deforested belts in the border part called Lesod of Plaiesii de Sus. The building at 116 Doboly is registered as a monument of Harghita county (1992).
The Balási Mansion (or the Imper Mansion, today village museum). The storeyed stone building stands in Imper, about 500 m from the centre of Plaiesii de Jos, in the western part of the village. It is registered among the historical monuments of Harghita county (1992). The building used to be the house of József Balási S. (1842-1848). It was built in late Baroque style; today it also houses a museum. The mansion has a symmetrical arrangement. Except its storey, each and every room has a vaulted ceiling and it has an arcaded loggia. In the large room of the storey used to be the library and the collection of arms. The archive preserved here in the mansion was destroyed in the two world wars, while the family archives of the inhabitants fell victims to the German bombs in 1944 and to the battle lasting several weeks.
Roman Catholic Chapel The chapel was built in the southern part of the village (the church of Plaiesii de Jos was shared with Imper).