The system of fortifications at Szendrõ was at one time one of the most important castles still in Hungarian hands; despite laying siege to it on a number of occasions, the Turkish forces could not capture it. Today, only some ruins of the former upper- and lower-castles remain.

During the 15th-16th centuries, the material from one of the towers of the lower-castle (which dated back to 1370) was used to construct the bell-tower of the present Calvinist church. The upper part of the tower, which was only completed later, in the 18th century, was built from timber and features a gallery.

The rustic-baroque style workshop, used for blue-dyeing cloth, was built between 1850 and 1860 from one of the towers of the 16th century city-wall. The building acquired its present name – “The Blue-Dye Workshop” – in the 19th century, when the blue-dye workers occupied it. As an Industrial Heritage Building it is presently exhibiting a collection of artefacts, representative of local history.

Construction of the Csáky Mansion, located in the centre of the settlement, was begun in 1694. The wall-remnants of an earlier manor-house were incorporated into the late-baroque style building. During the second-half of the 19th century, the mansion underwent significant alterations.
The main features preserving the baroque style - the triumphal arch, the vaulted porch, and the window gratings - can still be discerned today. The mansion is presently the centre of cultural life in the town – housing a library, museum and an art-gallery.