One of the most emblematic buildings in the village is the former private residence known as the Séra Mansion, commissioned by István Séra in the early years of the 19th century. Today it houses a museum of literary history and the Rustika sewing company. The founding charter of the mansion was discovered in 1997 inside the globe atop one of the tin gable finials, and is now preserved in the National Sekler Museum in Sepsiszentgyörgy; a copy is on display in the museum located on the upper storey of the Séra Mansion. After the Vienna Treaty (in which Nazi Germany returned northern Transylvania to Hungary), from 1940 to 1944 a post of the gendarmerie was stationed in the building. The gendarmes used the gable ornaments for target practice, which explains the bullet holes in the ancient document, which had to be restored to stop further deterioration of its paper, quite badly damaged by the rain water which trickled in over the decades. Later a village first aid station was set up here, and in 1997 the Reformed congregation of Illyefalva built a state-of-the-art medical centre for the village, equipped with service flats, a doctor’s and a dentist’s office, and in exchange the church was given leasehold rights to the Séra Mansion. The Reformed Church renovated the Mansion, which may be considered one of the finest examples of restored heritage buildings in the Háromszék district.