Heartsease shown within Powys
|OS grid reference|
|Sovereign state||United Kingdom|
|Fire||Mid and West Wales|
|UK Parliament||Brecon & Radnorshire|
Historically, it was part of the ancient Cantref of Maelienydd in the Kingdom of Powys. For historical population figures see Powys History Project. The hamlet lies on the A4113 road between Knighton and Ludlow and is a few hundred metres from the River Teme (Welsh: Afon Tefeidiad).
The settlement is the home of Radnor Hills, a business bottling local spring water.