Llanbister lies on the bank of the river Ithon in the rolling countryside of Powys, Mid Wales. The Ithon flows by the village before joining the river Wye at Newbridge on Wye, 13.5 miles away. Llanbister sits alongside the A483 from Newtown to Llandrindod Wells.

A 13th century church can be found in Llanbister, and is dedicated to St Cynllo. The Nave of St Cynllo's church may be c.1300 on basis of small lancets, though a church history claims there are older blocked windows in the north wall of the building. Most of its architecture can be attributed to the 14th Century and 16th Century, with sympathetic renovation in the early 20th Century. It is unusual for having the tower at the east end, has an interesting range of fixtures and fittings, and contains more dated inscriptions in stone and wood than any other church in Radnorshire, and perhaps in Powys.

An interesting story surrounds the village, involving two members of the Vaughan family. Shon Hir (Long John) and David Vaughan were caught in a fight together, when Shon killed David. After learning of her brother's death, Ellin Vaughan, also known as Ellin the Terrible, disguised herself as a man and arrived in Llanbister during an archery tournament. When she challenged Shon to a match, she killed him with her arrow and fled quickly. Later on she married another Black Vaughan, so called because he was just as fierce and dark as his wife.